Ahmad, M., R. Hasan, T. Naim, M. Ahmad, and T.B. Hanif (2003). The effect of isoniazid (INH) on erythrocyte sedimentation rate in the lizard, Uromastix hardwickii. Journal of Applied Sciences 38-9: 544-548. ISSN: 1607-8926.
Abstract: Erythrocyte sedimentation rate of isoniazid treated lizard was worked out. The gradual decrease for day 5 to day 10 and day 15 was found to be statistically significant. This is indicative of increase in erythrocyte membrane permeability with increase in the span of treatment. Newer cells are flooded in the blood stream due to loss of older cells. Newer cell resist sedimentation on day 10 and day 15.
Descriptors: reptiles, lizard, isoniazid, INH, effect, erythrocyte sedimentation rate, membrane permeability.
Ahmed, M., M. Ahmad, R. Hasan, A. Qureshi, and Z. Ahmed (2006). The effects of mefenamic acid on hematocrit of the lizard, Uromastix hardwickii. Pakistan Journal of Pharmaceutical Sciences 19(1): 48-51. ISSN: 1011-601X.
Abstract: Mefenamic acid is an analgesic, antipyretic and anti-inflammatory agent. In addition induces several hematological disturbances. Present study was conducted to determine the alterations in blood PCV of the lizard Uromastix hardwickii after the administration of 7.1 mg/ml; 10.5 mg/ml and 14.0 mg/ml mefenamic acid per individual per day for 12 days to 3 test groups. The mean values of PCV were 15.5+/-0.81%, 14.5+/-0.25% and 12.0+/-0.25% for 3 test groups respectively in comparison to 23.5+/-0.40% for control. Thus a significant dose dependant reduction in mean PCV per cent following the administration of mefenamic acid for 12 days indicates the extra vascular hemolysis due to destructive change in the red cell membrane through autoantibody mechanism.
Descriptors: lizard, anti-inflammatory agents, non-steroidal pharmacology, lizards blood, mefenamic acid pharmacology, anemia, hemolytic, autoimmune chemically induced, hematocrit.
Al Habsi, A.A., A.Y.A. Alkindi, I.Y. Mahmoud, D.W. Owens, T. Khan, and A. Al Abri (2006). Plasma hormone levels in the green turtles Chelonia mydas during peak period of nesting at Ras Al-Hadd-Oman. Journal of Endocrinology 191(1): 9-14. ISSN: 0022-0795.
NAL Call Number: 448.8 J8293
Descriptors: reptiles, green turtles, nesting, peak period, plasma hormone levels, estradiol, progesterone, testosterone, corticosterone.
Aldrich, K.J., D.K. Saunders, L.M. Sievert, and G. Sievert (2006). Comparison of erythrocyte osmotic fragility among amphibians, reptiles, birds and mammals. Transactions of the Kansas Academy of Science 109(3-4): 149-158. ISSN: 0022-8443.
NAL Call Number: 500 K13T
Descriptors: reptiles, erythrocyte, osmotic fragility, comparison study, amphibians, reptiles, mammals.
Alkindi, A.Y.A. and I.Y. Mahmoud (2002). A new method of sampling arterial blood from large sea turtles. Herpetological Review 33(4): 281-282. ISSN: 0018-084X.
NAL Call Number: QL640.H47
Descriptors: reptiles, large sea turtles, arterial blood, sampling, new method.
Azevedo, A., L. Casaletti, and L.O. Lunardi (2002). Morphology and histoenzymology of eosinophilic granulocytes in the circulating blood of the turtle (Chrysemys dorbignih). Journal of Submicroscopic Cytology and Pathology 34(3): 265-269. ISSN: 1122-9497.
Abstract: The studies on the characterization of eosinophils and neutrophils/heterophils of turtles are contradictory. Some authors have pointed out the existence of two distinct cell types: eosinophils and heterophils. Other authors have proposed that eosinophils and heterophils may be the same cells in different stages of maturation. These interpretations are based only on a morphological analysis. In the blood of the turtle (Chrysemys dorbignih), a South American freshwater species, there are two types of granulocytes with eosinophilic staining pattern: the first with round cytoplasmic granules and the second with ellipsoidal cytoplasmic granules. In the present study by using histoenzymological methods for the analyses of enzymological cellular content, we found that the cells with round cytoplasmic granules were positive for nonspecific esterase and the cells with ellipsoidal granules were positives for acid phosphatase, alkaline phosphatase, nonspecific esterase and peroxidase. The results show that these cells are distinct cells and that the cells with ellipsoidal cytoplasmic granules have the same histoenzymological characteristics as the neutrophils/heterophils of mammalians and other vertebrates.
Descriptors: reptiles, turtle, Chysemys dorbignih, blood, eosinophilic granulocytes, morphology, histoenzymology, neutrophils, heterophils.
Azevedo, A. and L.O. Lunardi (2003). Cytochemical characterization of eosinophilic leukocytes circulating in the blood of the turtle (Chrysemys dorbignih). Acta Histochemica 105(1): 99-105. ISSN: 0065-1281.
Abstract: Eosinophils and neutrophils are granulocytic leukocytes that are present in the blood of most vertebrates. Studies have been performed on lower vertebrates to understand the biological roles of the cells in defense mechanisms and to establish phylogenetic studies and new experimental models. Whether these 2 cell types exist in reptiles is a matter of controversy. In the blood of turtles there are 2 types of granulocytes that exhibit eosinophilia, one of them with round cytoplasmic granules and the other with elongated cytoplasmic granules. It has been suggested that these cells may be eosinophils in different stages of maturation but they also may be distinct cell types, i.e. eosinophils and neutrophils. In the present study, we characterized the 2 types of granulocytes that are present in the blood of Chrysemys dorbignih, using cytochemical techniques. Type I eosinophils showed activity of nonspecific esterase, peroxidase activity that is resistant to KCN, and basic proteins. Type II eosinophils exhibited activity of trimetaphosphatase, alkaline phosphatase, nonspecific esterase, peroxidase that is sensitive to KCN, and basic proteins. These observations indicate the existence of 2 distinct cell types in the blood of Chrysemys dorbignih, type I and type II eosinophils, that correspond to eosinophils and heterophils (neutrophils) of mammals and other vertebrates.
Descriptors: reptiles, turtle, Chrysemys dorbignih, circulating blood, eosinophilic leukocytes, cytochemical characterization, eosinophils, neutrophils.
Beraldo, F.H., R. Sartorello, M.L. Gazarini, W. Caldeira, and C.R.S. Garcia (2002). Red blood cells of the lizards Ameiva ameiva (squamata, teiidae) display multiple mechanisms to control cytosolic calcium. Cell Calcium 31(2): 79-87. ISSN: 0143-4160.
Descriptors: reptiles, red blood cells, lizards, mechanisms, control cytosolic calcium.
Birkedal, R. and H. Gesser (2004). Effects of hibernation on mitochondrial regulation and metabolic capacities in myocardium of painted turtle (Chrysemys picta). Comparative Biochemistry and Physiology. Part A, Molecular and Integrative Physiology 139(3): 285-291. ISSN: 1095-6433.
Abstract: Painted turtles hibernating during winter may endure long-term exposure to low temperature and anoxia. These two conditions may affect the aerobic capacity of a tissue and might be of particular importance to the cardiac muscle normally highly reliant on aerobic energy production. The present study addressed how hibernation affects respiratory characteristics of mitochondria in situ and the metabolic pattern of turtle myocardium. Painted turtles were acclimated to control (25 degrees C), cold (5 degrees C) normoxic and cold anoxic conditions. In saponin-skinned myocardial fibres, cold acclimation increased mitochondrial respiratory capacity and decreased apparent ADP-affinity. Concomitant anoxia did not affect this. Creatine increased the apparent ADP-affinity to similar values in the three acclimation groups, suggesting a functional coupling of creatine kinase to mitochondrial respiration. As to the metabolic pattern, cold acclimation decreased glycolytic capacity in terms of pyruvate kinase activity and increased lactate dehydrogenase (LHD) activity. Concomitant anoxia counteracted the cold-induced decrease in pyruvate kinase activity and increased creatine kinase activity. In conclusion, cold acclimation seems to increase aerobic and decrease anaerobic energy production capacity in painted turtle myocardium. Importantly, anoxia does not affect the mitochondrial functional integrity but seems to increase the capacity for anaerobic energy production and energy buffering.
Descriptors: reptiles, painted turtle, hibernation, effects, metabolic capacities, myocardium, mitochondrial regulation, anoxia, low temperature.
Broughton, B.R.S. and J.A. Donald (2003). Nitric oxide regulation of blood vessels in amphibians, reptiles and birds. Comparative Biochemistry and Physiology Part A Molecular and Integrative Physiology 134A(Suppl. 1): S47. ISSN: 1095-6433.
Descriptors: amphibians, reptiles, birds, nitric oxide, regulation, blood vessels, cardiovascular system, transport, circulation, meeting.
Notes: Meeting Information: Sixth International Congress of Comparative Physiology and Biochemistry, Mt Buller, Australia; February 02-07, 2003.
Broughton, B.R.S. and J.A. Donald (2007). Dual mechanisms for nitric oxide control of large arteries in the estuarine crocodile Crocodylus porosus. Journal of Experimental Biology 210(1): 129-137. ISSN: 0022-0949.
NAL Call Number: 442.8 B77
Descriptors: reptiles, nitric oxide control, large arteries, duel mechanisms, crocodile, systemic vasculature.
Bulte, G., C. Verly, and G. Blouin Demers (2006). An improved blood sampling technique for hatchling emydid turtles. Herpetological Review 37(3): 318-319. ISSN: 0018-084X.
NAL Call Number: QL640.H47
Descriptors: reptiles, emydid turtles, hatchling, improved blood sampling technique.
Casal, A.B. and J. Oros (2007). Morphologic and cytochemical characteristics of blood cells of juvenile loggerhead sea turtles (Caretta caretta). Research in Veterinary Science 82(2): 158-165. ISSN: 0034-5288.
Abstract: A morphologic classification based on the cytochemical characteristics of blood cells of 35 juvenile loggerhead sea turtles (Caretta caretta) is described. Cytochemical stains included benzidine peroxidase, chloroacetate esterase, alpha-naphthyl butyrate esterase (with and without sodium fluoride), acid phosphatase (with and without tartaric acid), Sudan black B, periodic acid-Schiff, and toluidine blue. The morphologic characteristics of erythrocytes were similar to those reported in green turtles. Six types of white blood cells were identified: heterophils, eosinophils, basophils, lymphocytes, monocytes and thrombocytes. Except for the basophils, the rest of the white blood cells from loggerhead turtles had different cytochemical characteristics compared to blood cells from other sea turtle species. The leukocyte differential count was different from that reported for other sea turtle species. Heterophils were the most numerous leukocytes from these loggerhead turtles, followed by lymphocytes, eosinophils, monocytes and basophils. This paper provides a morphologic classification of blood cells of loggerhead sea turtles that is useful for veterinary surgeons involved in sea turtle conservation.
Descriptors: reptiles, loggerhead sea turtles, Caretta caretta, blood cells, cytochemical characteristics, morphological, juvenile, veterinary medicine.
Chen, R.F., P.F. Yang, J.H. Hsieh, and C.T. Yen (2002). Vagal control of heart rate and ventricular contractility in turtles. Society for Neuroscience Abstract Viewer and Itinerary Planner 2002: Abstract No. 859.2. ISSN: 1529-2401.
Descriptors: reptiles, turtles, heart rate, ventricular contractility, vagal control, vagal nerve, meeting.
Notes: Meeting Information: 32nd Annual Meeting of the Society for Neuroscience, Orlando, Florida, USA; November 02-07, 2002.
Clark, T.D., T. Wang, P.J. Butler, and P.B. Frappell (2005). Factorial scopes of cardio-metabolic variables remain constant with changes in body temperature in the varanid lizard, Varanus rosenbergi. American Journal of Physiology. Regulatory, Integrative and Comparative Physiology 288(4): R992-R997. ISSN: print: 0363-6119; online: 1522-1490.
Abstract: The majority of information concerning the cardio-metabolic performance of varanids during exercise is limited to a few species at their preferred body temperature (T(b)) even though, being ectotherms, varanids naturally experience rather large changes in T(b). Although it is well established that absolute aerobic scope declines with decreasing T(b), it is not known whether changes in cardiac output (V(b)) and/or tissue oxygen extraction, (Ca(O2) - Cv(O2)), are in proportion to the rate of oxygen consumption (Vo(2)). To test this, we studied six Rosenberg's goannas (Varanus rosenbergi) while at rest and while maximally exercising on a treadmill both at 25 and 36 degrees C. During maximum exercise both at 25 and 36 degrees C, mass-specific rate of oxygen consumption (Vo(2kg)) increased with an absolute scope of 8.5 ml min(-1) kg(-1) and 15.7 ml min(-1) kg(-1), respectively. Interestingly, the factorial aerobic scope was temperature-independent and remained at 7.0 which, at each T(b), was primarily the result of an increase in V(bkg), governed by approximate twofold increases both in heart rate (f(H)) and cardiac stroke volume (V(Skg)). Both at 25 degrees C and 36 degrees C, the increase in V(bkg) alone was not sufficient to provide all of the additional oxygen required to attain maximal Vo(2kg), as indicated by a decrease in the blood convection requirement V(bkg)/Vo(2kg); hence, there was a compensatory twofold increase in (Ca(O2) - Cv(O2)). Although associated with an increase in hemoglobin-oxygen affinity, a decrease in T(b) did not impair unloading of oxygen at the tissues and act to reduce (Ca(O2) - Cv(O2)); both Ca(O2)) and Cv(O2)) were maintained across T(b). The change in Vo(2kg) with T(b), therefore, is solely reliant on the thermal dependence of V(bkg). Maintaining a high factorial aerobic scope across a range of T(b) confers an advantage in that cooler animals can achieve higher absolute aerobic scopes and presumably improved aerobic performance than would otherwise be achievable.
Descriptors: varanid lizard, body temperature, physiology, hemodynamic processes, metabolism, blood gas analysis, cardiac output, exertion, heart rate, oxygen consumption, seasons, temperature.
Crossley, D.A.I. and J. Altimiras (2005). Cardiovascular development in embryos of the American alligator Alligator mississippiensis: effects of chronic and acute hypoxia. Journal of Experimental Biology 208(1): 31-39. ISSN: 0022-0949.
NAL Call Number: 442.8 B77
Descriptors: reptiles, Alligator mississippiensis, circulatory system, cardiovascular development, acute hypoxia, embryo cardiovascular development, effects of chronic hypoxia, American alligator, North America.
Dbrowski, Z., I.S. Sano Martins, Z. Tabarowski, E. Witkowska Pelc, D.D. Spadacci Morena, K. Spodaryk, and D. Podkowa (2007). Haematopoiesis in snakes (Ophidia) in early postnatal development. Cell and Tissue Research 328(2): 291-299. ISSN: 0302-766X.
Abstract: The occurrence of haematopoiesis has been studied in various parts of the spine and in the ribs in four species of snakes (Boa constrictor L., Elaphe guttata L., Lamprophis fulaginosus Boie., Bothrops jararaca Wied.) from hatching until 150 days of postnatal development. Marrow spaces are formed by chondrolysis with various time frames depending on the studied species. Marrow cells egress to the general circulation in two ways: via migration through the endothelial cells lining the venous sinuses or by the rupture of protrusions. Erythroblasts are present in the lumen of marrow sinuses suggesting their final maturation there. Various relationships of the spleen to the pancreas have been found. No myelopoietic foci occur in the spleen, liver or kidney of any of the studied species. However, erythropoiesis (sparse islets) has been observed in Bothrops jararaca spleen.
Descriptors: reptiles, snakes, hematopoiesis, spine, ribs, hatching, postnatal development, marrow spaces, erythroblasts.
Deem, S.L., E.S. Dierenfeld, G.P. Sounguet, A.R. Alleman, C. Cray, R.H. Poppeng, T.M. Norton, and W.B. Karesh (2006). Blood values in free-ranging nesting leatherback sea turtles (Dermochelys coriacea) on the coast of the republic of Gabon. Journal of Zoo and Wildlife Medicine 37(4): 464-471. ISSN: 1042-7260.
NAL Call Number: SF601.J6
Descriptors: reptiles, leatherback sea turtles, blood values, hematology, plasma biochemistry, plasma protein electrophoresis.
Dunlap, K.D. (2006). Ontogeny and scaling of hematocrit and blood viscosity in western fence lizards, Sceloporus occidentalis. Copeia 2006(3): 535-538. ISSN: 0045-8511.
Descriptors: reptiles, fence lizards, Sceloporus occidentalis, hematocrit, blood vidcosity, ontogeny, scaling, volume.
Dutton, C.J. and P. Taylor (2003). A comparison between pre- and posthibernation morphometry, hematology, and blood chemistry in viperid snakes. Journal of Zoo and Wildlife Medicine 34(1): 53-58. ISSN: 1042-7260.
NAL Call Number: SF601.J6
Abstract: Snakes from temperate climates are often made to hibernate in zoos to stimulate reproduction. Unfortunately, deaths have occurred during and after hibernation. This study evaluated the health status, pre- and posthibernation, of 31 adult viperid snakes. It included morphometric measurements, hematology, and blood chemistry. No differences were seen in body weights and weight to length ratios between pre- and posthibernation examinations, suggesting that the overall condition of the snakes did not change. No differences were seen in hematologic and blood chemistry parameters, except that bile acids (3alpha-hydroxybile acids) decreased, the implications of which are unknown. Three individuals had markedly high plasma uric acid levels posthibernation; of these, two individuals died from extensive visceral gout and one recovered with fluid therapy. Viperid snakes should be clinically healthy, well hydrated, and in good body condition when they are put into hibernation. They should be maintained in an environment with sufficient humidity and should have access to water. Blood samples should be collected on arousal for measuring plasma uric acid levels. Changes in morphometry, hematology, and blood chemistry appear to be abnormal and should be investigated thoroughly.
Descriptors: reptiles, viperid snakes, prehibernation, posthibernation, comparison hematology, blood chemistry, morphometry.
Farmer, C.G. and J.W. Hicks (2002). The intracardiac shunt as a source of myocardial oxygen in a turtle, Trachemys scripta. Integrative and Comparative Biology 42(2): 208-215. ISSN: print: 1540-7063; online: 1557-7023.
NAL Call Number: QL1.I67
Descriptors: reptiles, turtle, Trachemys scripta, intracardiac shunt, myocardial oxygen, source.
Franklin, C.E. and F. Seebacher (2003). The effect of heat transfer mode on heart rate responses and hysteresis during heating and cooling in the estuarine crocodile Crocodylus porosus. Journal of Experimental Biology. 206(Pt 7): 1143-1151. ISSN: 0022-0949.
NAL Call Number: 442.8 B77
Abstract: The effect of heating and cooling on heart rate in the estuarine crocodile Crocodylus porosus was studied in response to different heat transfer mechanisms and heat loads. Three heating treatments were investigated. C. porosus were: (1) exposed to a radiant heat source under dry conditions; (2) heated via radiant energy while half-submerged in flowing water at 23 degrees C and (3) heated via convective transfer by increasing water temperature from 23 degrees C to 35 degrees C. Cooling was achieved in all treatments by removing the heat source and with C. porosus half-submerged in flowing water at 23 degrees C. In all treatments, the heart rate of C. porosus increased markedly in response to heating and decreased rapidly with the removal of the heat source. Heart rate during heating was significantly faster than during cooling at any given body temperature, i.e. there was a significant heart rate hysteresis. There were two identifiable responses to heating and cooling. During the initial stages of applying or removing the heat source, there was a dramatic increase or decrease in heart rate ('rapid response'), respectively, indicating a possible cardiac reflex. This rapid change in heart rate with only a small change or no change in body temperature (<0.5 degrees C) resulted in Q(10) values greater than 4000, calling into question the usefulness of this measure on heart rate during the initial stages of heating and cooling. In the later phases of heating and cooling, heart rate changed with body temperature, with Q(10) values of 2-3. The magnitude of the heart rate response differed between treatments, with radiant heating during submergence eliciting the smallest response. The heart rate of C. porosus outside of the 'rapid response' periods was found to be a function of the heat load experienced at the animal surface, as well as on the mode of heat transfer. Heart rate increased or decreased rapidly when C. porosus experienced large positive (above 25 W) or negative (below -15 W) heat loads, respectively, in all treatments. For heat loads between -15 W and 20 W, the increase in heart rate was smaller for the 'unnatural' heating by convection in water compared with either treatment using radiant heating. Our data indicate that changes in heart rate constitute a thermoregulatory mechanism that is modulated in response to the thermal environment occupied by the animal, but that heart rate during heating and cooling is, in part, controlled independently of body temperature.
Descriptors: reptiles, estuarine crocodile, Crocodylus porosus, heat transfer mode, heart rate response, effect, hysteresis, heating, cooling, body temperature.
Frappell, P.B., T.J. Schultz, and K.A. Christian (2002). The respiratory system in varanid lizards: determinants of O(2) transfer. Comparative Biochemistry and Physiology. Part A, Molecular and Integrative Physiology 133(2): 239-258. ISSN: 1095-6433.
Abstract: Varanids in general exhibit greater aerobic capacities than other lizards. In a similar approach to the extensive investigations undertaken in mammals, the respiratory system in varanids is examined in terms of oxygen transfer from the air to the blood during rest and sustained locomotory activity. The parameters controlling the transfer of O(2) through the various steps of the respiratory system are appropriate to meet the maximum demands for oxygen with one possible exception, circulatory convection. Ventilatory convection is maintained during maximal aerobic locomotion ensuring adequate pulmonary ventilation and the protection of alveolar P(O(2)). Little evidence exists to indicate a mechanically imposed constraint to breathe and the possibility of a gular pump acting to assist ventilation, as a general feature of varanids remains to be determined. Alterations in the relative contributions of the ventilation-perfusion ratio, pulmonary diffusion, diffusion equilibrium and right-left shunts preserved the alveolar-arterial P(O(2)) difference, ensuring that arterial oxygenation was maintained. In those species where increases in cardiac output were limited, maximum O(2) transfer was achieved through increased extraction of oxygen at the tissues. Overall, the interrelationship of adjacent steps in the respiratory system ensures that one step cannot become limiting. Compensatory changes occur in various parameters to offset those parameters that are 'limited'. The high aerobic activity of varanid lizards would not be achievable without a compensated circulatory convection.
Descriptors: reptiles, varanid lizards, respiratory system, oxygen transfer, aerobic capacities, blood, air.
Gal, J. (2004). A hullok verkepzo es keringesi szerveinek fontosabb megbetegedesei. [Major diseases of hemopoetic and circulatory systems of reptiles]. KisallatPraxis 5(3): 134-136. ISSN: 1585-9142.
NAL Call Number: SF981.K573
Descriptors: reptiles, major diseases, hemopoetic system, circulatory system.
Language of Text: Hungarian; Summary in English.
Gal, J. (2003). Meszsolerakodas vitorlas agama (Hydrosaurus amboinensis) verereiben. [Calcification in blood vessels of a sailfin lizard (Hydrosaurus amboinensis)]. Magyar Allatorvosok Lapja 125(11): 687-689. ISSN: 0025-004X.
Descriptors: reptiles, lizard, blood vessels, calcification, nutrition.
Language of Text: Hungarian; Summary in English.
Galli, G., E.W. Taylor, and T. Wang (2004). The cardiovascular responses of the freshwater turtle Trachemys scripta to warming and cooling. Journal of Experimental Biology. 207(Pt 9): 1471-1478. ISSN: 0022-0949.
NAL Call Number: 442.8 B77
Abstract: Seven freshwater turtles Trachemys scripta were instrumented with flow probes and cannulated for blood pressure measurements. The turtles were warmed from 24 to 34 degrees C, and cooled down to 24 degrees C, with and without atropine. Animals exhibited a hysteresis of heart rate and blood flow to both the pulmonary and systemic circulations, which was not cholinergically mediated. Blood pressure remained constant during both warming and cooling, while systemic resistance decreased during heating and increased during cooling, indicating a barostatic response. There was a large right-to-left (R-L) shunt during warming and cooling in untreated animals, which remained relatively constant. Atropinisation resulted in a large L-R shunt, which decreased during warming and increased during cooling. Nevertheless, heating rates were the same in untreated and atropinised animals, and cooling rates were significantly longer in atropinised animals, indicating that shunt patterns contribute little to heat exchange.
Descriptors: reptiles, freshwater turtle, Trachemys scripta, cardiovascular responses, warming, cooling, atropine, blood pressure, body temperature, shunt.
Galli, G.L., H. Gesser, E.W. Taylor, H.A. Shiels, and T. Wang (2006). The role of the sarcoplasmic reticulum in the generation of high heart rates and blood pressures in reptiles. Journal of Experimental Biology. 209(Pt 10): 1956-1963. ISSN: 0022-0949.
NAL Call Number: 442.8 B77
Abstract: The functional significance of the sarcoplasmic reticulum (SR) in the generation of high heart rates and blood pressures was investigated in four species of reptile; the turtle, Trachemys scripta; the python, Python regius, the tegu lizard, Tupinanvis merianae, and the varanid lizard, Varanus exanthematicus. Force-frequency trials and imposed pauses were performed on ventricular and atrial tissue from each species with and without the SR inhibitor ryanodine, and in the absence and presence of adrenaline. In all species, an imposed pause of 1 or 5 min caused a post-rest decay of force, and a negative force-frequency response was observed in all species within their in vivo frequency range of heart rates. These relationships were not affected by either ryanodine or adrenaline. In ventricular strips from varanid lizards and pythons, ryanodine caused significant reductions in twitch force within their physiologically relevant frequency range. In atrial tissue from the tegu and varanid lizards, SR inhibition reduced twitch force across the whole of their physiological frequency range. In contrast, in the more sedentary species, the turtle and the python, SR inhibition only decreased twitch force at stimulation frequencies above maximal in vivo heart rates. Adrenaline caused an increase in twitch force in all species studied. In ventricular tissue, this positive inotropic effect was sufficient to overcome the negative effects of ryanodine. In atrial tissue however, adrenaline could only ameliorate the negative effects of ryanodine at the lower pacing frequencies. Our results indicate that reptiles recruit Ca2+ from the SR for force development in a frequency and tissue dependent manner. This is discussed in the context of the development of high reptilian heart rates and blood pressures.
Descriptors: reptiles, turtle, Trachemys scripta, tegu lizard, Tupinanvis merianae, python, Python regius, varanid lizaed, Varanus exanthematicus, blood pressure, heart rate, lizards physiology, sarcoplasmic reticulum, myocardium.
Gelli, D., M. Morgante, V. Ferrari, A. Mollo, D. Freggi, and S. Romagnoli (2004). Hematologic, serum biochemical, and serum electrophoretic patterns in loggerhead sea turtles (Caretta caretta). Proceedings of the Annual Conference of the Association of Reptilian and Amphibian Veterinarians 11: 149-152. ISSN: 1529-9561.
NAL Call Number: SF996.A77
Descriptors: reptiles, loggerhead sea turtles, Caretta caretta, hematologic, serum biochemical, serum electrophoretic, patterns.
Gordos, M.A., C.E. Franklin, C.J. Limpus, and G. Wilson (2004). Blood-respiratory and acid-base changes during extended diving in the bimodally respiring freshwater turtle Rheodytes leukops. Journal of Comparative Physiology. B, Biochemical, Systemic, and Environmental Physiology 174(4): 347-354. ISSN: print: 0174-1578; online: 1432-136X.
NAL Call Number: QP33.J681
Abstract: Changes in blood-gas, acid-base, and plasma-ion status were investigated in the bimodally respiring turtle, Rheodytes leukops, during prolonged dives of up to 12 h. Given that R. leukops routinely submerges for several hours, the objective of this study was to determine whether voluntarily diving turtles remain aerobic and simultaneously avoid hypercapnic conditions over increasing dive lengths. Blood PO(2), PCO(2), and pH, as well as plasma concentrations of lactate, glucose, Na(+), K(+), Cl(-), total Ca, and total Mg were determined in venous blood collected from the occipital sinus. Blood PO(2) declined significantly with dive length; however, oxy-haemoglobin saturation remained greater than 30% for all R. leukops sampled. No changes were observed in blood PCO(2), pH, [HCO(3)(-)], or plasma glucose, with increasing dive length. Despite repeated dives lasting more than 2 h, plasma lactate remained less than 3 mmol l(-1) for all R. leukops sampled, indicating the absence of anaerobiosis. Compensatory acid-base adjustments associated with anaerobiosis (e.g. declining [Cl(-)], increasing total [Ca] and [Mg]) were likewise absent, with plasma-ion concentrations remaining stable with increasing dive length. Results indicate that R. leukops utilises aquatic respiration to remain aerobic during prolonged dives, thus effectively avoiding the development of a metabolic and respiratory acidosis.
Descriptors: reptiles, freshwater turtle, Rheodytes leukops, extended diving, acid-base changes, blood-respiratory, bimodally respiring.
Goris, R.C., Y. Atobe, M. Nakano, K. Funakoshi, and K. Terada (2007). Blood flow in snake infrared organs: response-induced changes in individual vessels. Microcirculation 14(2): 99-110. ISSN: 1073-9688.
Abstract: OBJECTIVE: In the past the microkinetics of blood flow in the infrared pit organs of pit vipers has been studied with Doppler flowmetry using various infrared stimuli such as a human hand or soldering iron at various distances, lasers of various wavelengths, etc. Quick-acting variations in blood flow were recorded, and interpreted as a cooling mechanism for avoiding afterimage in the infrared receptors. However, the Doppler measurements provided only the summation of blood flow in a number of vessels covered by the sensing probe, but did not give data on flow in individual vessels. METHODS: In the present work the authors introduced into the bloodstream of Gloydius and Trimeresurus pit vipers fluorescent microspheres labeled with fluorescein isothiocyanate (FITC) contained in a solution of FITC-dextran in physiological saline. They observed the passage of the microspheres through individual pit organ vessels with a fluorescent microscope to which was attached a high-speed video camera and image intensifier. Output of the camera was recorded before, during, and after stimulus with a 810-nm diode laser. Recording was done at 250 frames/s on high-speed video apparatus and downloaded to a hard disk. Disk files were loaded into proprietary software and particles were tracked and average velocities calculated. The data were then tested for significance by ANOVA with post hoc tests. RESULTS: A significant (p<.05) increase in blood velocity was found at the focal point of the stimulus laser, but not anywhere removed from this point. Proximal severing of the pit sensory nerves caused degeneration of the pit receptor terminals and abolished stimulus-induced blood flow changes, but did not affect normal blood flow. CONCLUSIONS: The authors conclude that the receptors themselves are directly and locally controlling the smooth muscle elements of the blood vessels, in response to heating of the receptors by infrared radiation. They speculate that the heavy vascularization constitutes a cooling system for the radiation-encoding receptors, and further that the agent of control may be a volatile neuromediator such as nitric oxide.
Descriptors: reptiles, snake, infrared pit organs, blood flow, induced changes, microkinetics, smooth muscle elements, blood vessels.
Hanley, C.S., S.J. Hernandez Divers, S. Bush, and K.S. Latimer (2004). Comparison of the effect of dipotassium ethylenediaminetetraacetic acid and lithium heparin on hematologic values in the green iguana (Iguana iguana). Journal of Zoo and Wildlife Medicine 35(3): 328-332. ISSN: 1042-7260.
NAL Call Number: SF601.J6
Abstract: We compared the effects of dipotassium ethylenediaminetetraacetic acid (EDTA) and lithium heparin on hematologic values of green iguanas (Iguana iguana). Thirty-two privately owned sibling iguanas had blood drawn, and the sample was divided into three components: an EDTA tube, a heparin tube, and a nonanticoagulated blood smear. A full reptilian complete blood count was performed on each anticoagulated sample, and white blood cell (WBC) and leukocyte differential counts were performed on the whole-blood smears. Heparin and EDTA samples differed significantly in absolute values of thrombocytes, WBC, heterophils, and monocytes. The EDTA had no significant effect on the packed cell volume or plasma protein values, and the white blood count and differential counts produced with EDTA were more similar to those of the nonanticoagulated blood smear than were the counts produced with heparin.
Descriptors: reptiles, green iguana, hematologic values, dipotassium ethylenediaminetetraacetic acid, lithium heparin, anticoagulants, effects, blood count.
Harms, C.A., K.M. Mallo, P.M. Ross, and A. Segars (2003). Venous blood gases and lactates of wild loggerhead sea turtles (Caretta caretta) following two capture techniques. Journal of Wildlife Diseases 39(2): 366-374. ISSN: 0090-3558.
NAL Call Number: 41.9 W64B
Abstract: During summer of 2001, venous blood gases were determined in loggerhead sea turtles (Caretta caretta) captured by trawl (n = 16) in coastal waters of South Carolina and Georgia (USA) as part of a sea turtle census program and captured in pound nets (n = 6) in coastal North Carolina (USA) during a study of sea turtle population biology. Trawls were towed for 30 min, so turtles captured were forcibly submerged for < or = 30 min. Pound nets are passive gear in which fish and sea turtles are funneled into a concentrated area and removed periodically. Sea turtles in pound nets are free to surface and to feed at will. Blood was obtained from the dorsal cervical sinus as quickly as possible after landing on the boat (range 2-10 min trawl, 1-2 min pound net) and at 30 min after landing just prior to release. Blood gases including pH, partial pressures of O2 and CO2 (pO2, pCO2), and lactate were measured within 10 min. Instrument measurements for pH, pO2, and pCO2 made at 37 C were corrected to cloacal temperature and HCO3- was calculated from temperature-corrected pH and pCO2. Venous blood pH and bicarbonate were higher, and pO2 and lactate were lower from pound net-captured turtles compared to trawl captured turtles at the initial sampling time. In pound net turtles, pH and bicarbonate declined and lactate increased during 30 min on deck. In trawled sea turtles, venous blood pH increased and pCO2 and pO2 decreased during the 30 min on deck. Both capture systems caused perturbations in blood gas, acid-base, and lactate status, though alterations were greater in trawl captured turtles.
Descriptors: reptiles, loggerhead sea turtles, Caretta caretta, wild, capture techniques, venous blood gases, lactates, acid-base.
Hicks, J.W. (2002). The physiological and evolutionary significance of cardiovascular shunting patterns in reptiles. News in Physiological Sciences 17: 241-245. ISSN: print: 0886-1714; online: 1522-161X.
Abstract: The morphology of the reptilian heart results in the mixing of oxygenated and deoxygenated blood (cardiac shunts). In birds and mammals cardiac shunts are detrimental, but in reptiles this condition is often considered a derived trait, conveying important physiological functions and favored by natural selection. Alternative views are advanced suggesting that, in reptiles, cardiac shunts represent either an ancestral condition or an embryonic trait.
Descriptors: reptiles, cardiovascular physiology, evolution, heart physiology, shunting patterns, significance, heart, blood.
Hochscheid, S., F. Bentivegna, and J.R. Speakman (2002). Regional blood flow in sea turtles: implications for heat exchange in an aquatic ectotherm. Physiological and Biochemical Zoology 75(1): 66-76. ISSN: 1522-2152.
NAL Call Number: QL1.P52
Abstract: Despite substantial knowledge on thermoregulation in reptiles, the mechanisms involved in heat exchange of sea turtles have not been investigated in detail. We studied blood flow in the front flippers of two green turtles, Chelonia mydas, and four loggerhead turtles, Caretta caretta, using Doppler ultrasound to assess the importance of regional blood flow in temperature regulation. Mean blood flow velocity and heart rate were determined for the water temperature at which the turtles were acclimated (19.3 degrees-22.5 degrees C) and for several experimental water temperatures (17 degrees-32 degrees C) to which the turtles were exposed for a short time. Flipper circulation increased with increasing water temperature, whereas during cooling, flipper circulation was greatly reduced. Heart rate was also positively correlated with water temperature; however, there were large variations between individual heart rate responses. Body temperatures, which were additionally determined for the two green turtles and six loggerhead turtles, increased faster during heating than during cooling. Heating rates were positively correlated with the difference between acclimation and experimental temperature and negatively correlated with body mass. Our data suggest that by varying circulation of the front flippers, turtles are capable of either transporting heat quickly into the body or retaining heat inside the body, depending on the prevailing thermal demands.
Descriptors: reptiles, sea turtles, Caretta caretta, regional blood flow, heat exchange, implications, flipper blood flow, body temperatures.
Jackson, D.C. and J. Liu (2002). The importance of blood flow for lactate uptake into shells of anoxic turtles. FASEB Journal 16(4): A425. ISSN: 0892-6638.
NAL Call Number: QH301.F3
Descriptors: reptiles, turtles, anoxic, lactate uptake, blood flow, importance, meeting.
Notes: Meeting Information: Annual Meeting of the Professional Research Scientists on Experimental Biology, New Orleans, Louisiana, USA; April 20-24, 2002.
Kakizoe, Y., K. Sakaoka, F. Kakizoe, M. Yoshii, H. Nakamura, Y. Kanou, and I. Uchida (2007). Successive changes of hematologic characteristics and plasma chemistry values of juvenile loggerhead turtles (Caretta caretta). Journal of Zoo and Wildlife Medicine 38(1): 77-84. ISSN: 1042-7260.
Abstract: Hematologic characteristics and plasma chemistry values of juvenile loggerhead turtles (Caretta caretta) from the ages of 1 mo to 3 yr were obtained to establish baseline values. Five clinically normal loggerhead turtles were selected from the same clutch and raised in an indoor artificial nesting beach. Blood samples were successively collected and examined for various blood characteristics for a maximum total of 15 times. Hematologic characteristics, including packed cell volume, white blood cell counts, and white blood cell differentials; and plasma chemistry values, including total bilirubin, total protein, albumin, glutamic oxaloacetic transaminase, glutamic pyruvic transaminase, gamma-glutamic transpeptidase, creatinine, blood urea nitrogen, uric acid, alkaline phosphatase, amylase, triglyceride, total cholesterol, ionized sodium, ionized potassium and ionized chlorine, were measured. These results were used to establish a hematology and blood chemistry baseline for captive juvenile loggerhead turtles and will aid in their medical management.
Descriptors: reptiles, loggerhead turtles, Caretta caretta, juvenile, hematologic characteristics, changes, plasma chemistry values, baseline values.
Keller, J.M., J.R. Kucklick, and P.D. McClellan Green (2004). Organochlorine contaminants in loggerhead sea turtle blood: extraction techniques and distribution among plasma and red blood cells. Archives of Environmental Contamination and Toxicology 46(2): 254-264. ISSN: 0090-4341.
NAL Call Number: TD172.A7
Descriptors: reptiles, sea turtle, Caretta caretta, organochlorine compounds, organochlorine pesticides, monitoring, blood plasma, erythrocytes, extraction techniques, plasma, red blood cells.
Knotek, Z., Z. Knotkova, J. Doubek, S. Pejrilova, and K. Hauptman (2003). Plasma biochemistry in female green iguanas (Iguana iguana) with calcium metabolism disorders. Acta Veterinaria Brno 72(2): 183-189. ISSN: 0001-7213.
NAL Call Number: SF604.B7
Descriptors: reptiles, female green iguanas, Iguana iguana, plasma biochemistry, calcium metabolism disorders, diagnostic tool.
Language of Text: Czech.
Krosniunas, E.H. and J.W. Hicks (2003). Cardiac output and shunt during voluntary activity at different temperatures in the turtle, Trachemys scripta. Physiological and Biochemical Zoology 76(5): 679-694. ISSN: 1522-2152.
NAL Call Number: QL1.P52
Abstract: Red-eared slider turtles (Trachemys scripta) were chronically instrumented with blood flow probes for a long-term study of voluntary behavior in an enriched laboratory setting. Cardiovascular measures consisting of total cardiac output (Q(tot)), pulmonary blood flow (Q(pul)), systemic blood flow (Q(sys)), net cardiac shunt (Q(shunt)), heart rate (HR), and stroke volume (SV) were obtained during spontaneous activity at a constant body temperature (Tb=2 degrees C) and at unstable (variable) T(b)'s ranging from 19 degrees to 37 degrees C. The effects of temperature and activity differed between the pulmonary and systemic circuits, with increases in Q(sys) due to HR alone, while both HR and SV contributed to gains in Q(pul). At stable 20 degrees C, cardiovascular responses during diving, submerged swimming, and walking were qualitatively similar, and increases in Q(tot) during activity ( approximately 2 x resting levels) were due to greater gains in Q(pul) than Q(sys). At unstable T(b)'s and in general, net Q(shunt) while active depended on the integration of individual physiological influences such as heating, cooling, and initial behavioral state acting on the cardiovascular system. During activity, net left-to-right (L-R) shunts predominated at constant T(b) of 20 degrees C (mean shunt fraction approximately 30%-40%), while both net L-R and right-to-left (R-L) shunts of varying size were found at unstable T(b)'s (19 degrees - 37 degrees C).
Descriptors: reptiles, turtle, Trachemys scripta, cardiac output, shunt, voluntary activity, different tenperatures, body temperature, heart rate.
Kubalek, S., R. Mischke, and M. Fehr (2002). Investigations on blood coagulation in the green iguana (Iguana iguana). Journal of Veterinary Medicine. A, Physiology, Pathology, Clinical Medicine 49(4): 210-216. ISSN: 0931-184X.
NAL Call Number: 41.8 Z5
Abstract: The prothrombin time (PT), activated partial thromboplastin time (APTT), thrombin time, kaolin clotting time (KCT), dilute Russell's viper venom time (DRVVT) and reptilase time, as well as five different plasma fibrinogen assays [gravimetry, Jacobsson method (extinction at 280 nm), Millar method (heat precipitation), kinetic turbidometry, Clauss method] and resonance thrombography were performed in 26 clinically healthy green iguanas. All assays were carried out in comparison with pooled normal canine plasma. In iguana plasma, the PT [median (x0.50) = 453-831 s, dependent on the reagent], APTT (x0.50 = 170-242 s, dependent on the reagent), thrombin time (x0.50 = 118 - > 1000 s, dependent on thrombin activity), KCT (x0.50 = 274 s), DRVVT (x0.50 = 349 s) and reptilase time (all samples > 1000 s) were widely scattered at the limit of measurability. Only fibrinogen concentrations measured using the Jacobsson method (x0.50 = 4.40 g/l) correlated well (r = 0.91) with gravimetry (x0.50 = 4.22 g/l). The results of this study indicate a limited suitability and a confined diagnostic significance of the selected methods in the green iguana. This may be caused by the species specificity of certain components of the reagents used, as well as a less optimal test system, i.e. relationship of test reagent to clotting factor concentrations in iguana plasma.
Descriptors: reptiles, green iguana, Iguana iguana, blood coagulation, investigations, prothrombin time, clotting factor, iguana plasma, thrombin time.
Litvinov, N. and S. Ganshchuk (2005). Environment and body temperatures of reptiles in Volga-Ural region. Russian Journal of Herpetology 12(Suppl.): 179-182. ISSN: 1026-2296.
Descriptors: reptiles, body temperature, environmental temperature, cardiovascular response, circulatory system, Eurasia, Volga Ural region.
Lopez Olvera, J.R., J. Montane, I. Marco, A. Martinez Silvestre, J. Soler, and S. Lavin (2003). Effect of venipuncture site on hematologic and serum biochemical parameters in marginated tortoise (Testudo marginata). Journal of Wildlife Diseases 39(4): 830-836. ISSN: 0090-3558.
NAL Call Number: 41.9 W64B
Descriptors: reptiles, tortoise, Testudo marginata, venipuncture site, effect, hematologic parameters, serum biochemical parameters, marginated tortoise, blood samples.
Maginniss, L.A., S.A. Ekelund, and G.R. Ultsch (2004). Blood oxygen transport in common map turtles during simulated hibernation. Physiological and Biochemical Zoology 77(2): 232-241. ISSN: 1522-2152.
NAL Call Number: QL1.P52
Abstract: We assessed the effects of cold and submergence on blood oxygen transport in common map turtles (Graptemys geographica). Winter animals were acclimated for 6-7 wk to one of three conditions at 3 degrees C: air breathing (AB-3 degrees C), normoxic submergence (NS-3 degrees C), and hypoxic (PO2=49 Torr) submergence (HS-3 degrees C). NS-3 degrees C turtles exhibited a respiratory alkalosis (pH 8.07; PCO2=7.9 Torr; [lactate]=2.2 mM) relative to AB-3 degrees C animals (pH 7.89; PCO2=13.4 Torr; [lactate]=1.1 mM). HS-3 degrees C animals experienced a profound metabolic acidosis (pH 7.30; PCO2=7.9 Torr; [lactate]=81 mM). NS-3 degrees C turtles exhibited an increased blood O2 capacity; however, isoelectric focusing revealed no seasonal changes in the isohemoglobin (isoHb) profile. Blood O2 affinity was significantly increased by cold acclimation; half-saturation pressures (P50's) for air-breathing turtles at 3 degrees and 22 degrees C were 6.5 and 18.8 Torr, respectively. P50's for winter animals submerged in normoxic and hypoxic water were 5.2 and 6.5 Torr, respectively. CO2 Bohr slopes (Delta logP50/Delta pH) were -0.15, -0.16, and -0.07 for AB-3 degrees C, NS-3 degrees C, and HS-3 degrees C turtles, respectively; the corresponding value for AB-22 degrees C was -0.37. The O2 equilibrium curve (O2EC) shape was similar for AB-3 degrees C and NS-3 degrees C turtles; Hill plot n coefficients ranged from 1.8 to 2.0. The O2EC shape for HS-3 degrees C turtles was anomalous, exhibiting high O2 affinity below P50 and a right-shifted segment above half-saturation. We suggest that increases in Hb-O2 affinity and O2 capacity enhance extrapulmonary O2 uptake by turtles overwintering in normoxic water. The anomalous O2EC shape and reduced CO2 Bohr effect of HS-3 degrees C turtles may also promote some aerobic metabolism in hypoxic water.
Descriptors: reptiles, map turtles, blood oxygen transport, simulated hibernation, acclimatization, cold, hypothermia, oxygen blood, metabolism.
Martinez Silvestre, A., I. Marco, M.A. Rodriguez Dominguez, S. Lavin, and R. Cuenca (2005). Morphology, cytochemical staining, and ultrastructural characteristics of the blood cells of the giant lizard of El Hierro (Gallotia simonyi). Research in Veterinary Science 78(2): 127-134. ISSN: 0034-5288.
NAL Call Number: 41.8 R312
Abstract: The object of this study was to examine the erythrocytes, leukocytes and thrombocytes of the giant lizard (Gallotia simonyi) by light and electron (TEM) microscopy, and cytochemical staining. Smears were prepared from blood from the ventral coccygeal vein of 10 healthy adult lizards (five males and five females) from the Giant Lizard of El Hierro Reproduction and Research Centre, Canary Islands, Spain. The cytochemical stains used were: benzidine peroxidase (BP), chloroacetate esterase (CAE), alpha-naphthyl acetate esterase (ANAE), acid phosphatase (AP), periodic acid-Schiff (PAS), toluidine blue (TB) and May-Grunwald-Giemsa (MGG). Electron microscopy was also performed on all samples. Heterophils had granules that were heterogeneous in both size and electron density, and stained with BP, PAS and ANAE. Eosinophil granules were homogeneously electron-dense and stained for AP, CAE and ANAE. Basophils had both highly and moderately electron-dense granules, and stained with TB and ANAE. Azurophil granules were of low electron-density and stained for AP, CAE and ANAE. Azurophil cytoplasm was vacuolated on TEM. The cytoplasm of lymphocytes contained many ribosomes and was positive for AP. Monocytes had a large nucleus and a vacuolated cytoplasm but did not stain by any of the cytochemical methods used. Thrombocytes had a relatively large nucleus but little cytoplasm; they did not stain cytochemically. The blood cells of the giant lizards of El Hierro differ from those of other members of the Order Squamata both morphologically and cytochemically. The variation in cytochemical responses in the blood of reptiles makes it necessary to study species individually if meaningful clinical decisions are to be made.
Descriptors: giant lizard of El Hierro, Gallotia simonyi, blood cells, erythrocytes, leukocytes, thrombocytes, morphology, cytochemical staining, ultrastructural characteristics.
Martinez Silvestre, A., J.A. Mateo, and J. Pether (2003). Electrocardiographic parameters in the Gomeran giant lizard, Gallotia bravoana. Journal of Herpetological Medicine and Surgery 13(3): 22-25. ISSN: 1529-9651.
NAL Call Number: SF997.5.R4 B85
Descriptors: reptiles, Gomeran giant lizard, Gallotia bravoana, heart rate, electrocardiographic parameters.
Martinez Silvestre, A., M.A. Rodriguez Dominguez, J.A. Mateo, J. Pastor, I. Marco, S. Lavin, and R. Cuenca (2004). Comparative haematology and blood chemistry of endangered lizards (Gallotia species) in the Canary Islands. Veterinary Record 155(9): 266-269. ISSN: 0042-4900.
NAL Call Number: 41.8 V641
Abstract: Blood samples were taken from the ventral coccygeal vein of 15 El Hierro giant lizards (Gallotia simonyi) (seven females and eight males), six La Gomera giant lizards (Gallotia bravoana) (four males and two females) and four Tenerife giant lizards (Gallotia intermedia) (two males and two females), and 31 blood parameters were measured. Among the haematological parameters there were significant differences between the three species in heterophils, azurophils and lymphocytes, but no significant differences in red blood cell count, white blood cell count, haemoglobin, packed-cell volume, monocytes, eosinophils and basophils. In terms of blood chemistry there were significant differences between the three species in cholesterol, triglycerides, glucose, sodium, chloride, urea, uric acid, total proteins, prealbumin, albumin and gamma globulins, but no significant differences in calcium, potassium, aspartate aminotransferase, alanine aminotransferase, creatine kinase, bile acids, alpha-1 and alpha-2 globulins and beta globulins.
Descriptors: reptiles, endangered lizards, La Gomera giant lizards, Gallotia species, blood chemistry, comparative haematology, Hierro giant lizards, Tenerife giant lizards, blood parameters, Canary Islands.
Martinez Silvestre, A., J.L. Silva, and L. Silveira (2002). Hematologia y bioquimica sanguinea del lagarto gigante de El Hierro (Gallotia simonyi) en cautividad. [Hematology and blood chemistry of captive El Hierro giant lizard (Gallotia simonyi).]. Revista Espanola De Herpetologia 16: 5-10. ISSN: 0213-6686.
Descriptors: reptiles, giant lizard, Gallotia simonyi, blood chemistry, hematology, captive.
Language of Text: Spanish; Summary in English and Spanish.
Melo, M.B., S. Bordin, A.S.S. Duarte, S.H. Ogo, M.A. Torsoni, S.T.O. Saad, and F.F. Costa (2003). Molecular characterization of hemoglobin alpha-D chains from Geochelone carbonaria and Geochelone denticulata land turtles. Comparative Biochemistry and Physiology Part B Biochemistry and Molecular Biology 134(2): 389-395. ISSN: 1096-4959.
Abstract: In order to help elucidate the evolution of alpha-globins, the complete cDNA and amino acid sequences of Geochelone carbonaria and Geochelone denticulata land turtles alpha-D chains have been described. In G. carbonaria, the cDNA is 539 bp with ATG start codon located at position 46, TGA stop codon at position 469 and AATAAA polyadenylation signal at position 520. In G. denticulata, the cDNA is 536 bp with ATG start codon located at position 46, TGA stop codon at position 469 and AATAAA polyadenylation signal at position 517. Both cDNAs codify 141 amino acid residues, differing from each other in only four amino acid residues. When comparing with human Hb alpha-chain, alterations in important regions can be noted: alpha110 Ala-Gly, alpha114 Pro-Gly, alpha117 Phe-Tyr and alpha122 His-Gln. There is a high homology between the amino acids of these turtles when compared with chicken alpha-D chains, progressively decreasing when compared with human, crocodile, snake, frog and fish alpha-chains. Phylogenetic analysis of alpha-D chains shows that those of turtles are closer to those of birds than to snakes and lizards.
Descriptors: reptiles, land turtles, Geochelone carbonatia, Geochelone denticulata, cDNA, amino acid sequences, birds, snakes, lizards, crocodiles.
Merchant, M. and A. Britton (2006). Characterization of serum complement activity of saltwater (Crocodylus porosus) and freshwater (Crocodylus johnstoni) crocodiles. Comparative Biochemistry and Physiology. Part A, Molecular and Integrative Physiology 143(4): 488-493. ISSN: 1095-6433.
Abstract: We employed a spectroscopic assay, based on the hemolysis of sheep red blood cells (SRBCs), to assess the innate immune function of saltwater and freshwater crocodiles in vitro. Incubation of serum from freshwater and saltwater crocodiles with SRBCs resulted in concentration-dependent increases in SRBC hemolysis. The hemolytic activity occurred rapidly, with detectable activity within 2 min and maximum activity at 20 min. These activities, in both crocodilian species, were heat sensitive, unaffected by 20 mM methylamine, and completely inhibited by low concentrations of EDTA, suggesting that the alternative serum complement cascade is responsible for the observed effects. The hemolytic activities of the sera were inhibited by other chelators of divalent metal ions, such as phosphate and citrate. The inhibition of SRBC hemolysis by EDTA could be completely restored by the addition of 10 mM Ca2+ or Mg2+, but not Ba2+, Cu2+ or Fe2+, indicating specificity for these metal ions. The serum complement activities of both crocodilians were temperature-dependent, with peak activities occurring at 25-30 degrees C and reduced activities below 25 degrees C and above 35 degrees C.
Descriptors: reptiles, saltwater (Crocodylus porosus) and freshwater (Crocodylus johnstoni) crocodiles, crocodiles blood, complement system proteins metabolism, barium pharmacology, calcium pharmacology, copper pharmacology, edetic acid pharmacology, erythrocytes metabolism, fresh water, hemolysis drug effects, iron pharmacology, kinetics, magnesium pharmacology, temperature.
Metin, K., O. Turkozan, F. Kargin, Y. Basimoglu Koca, E. Taskavak, and S. Koca (2006). Blood cell morphology and plasma biochemistry of the captive European pond turtle Emys orbicularis. Acta Veterinaria Brno 75(1): 49-55. ISSN: 0001-7213.
NAL Call Number: SF604.B7
Descriptors: reptiles, European pond turtle, Emys orbicularis, blood cell morphology, plasma biochemistry, captive, micronucleated erythrocytes.
Language of Text: Czech; English.
Munns, S.L., L.K. Hartzler, A.F. Bennett, and J.W. Hicks (2005). Terrestrial locomotion does not constrain venous return in the American alligator, Alligator mississippiensis. Journal of Experimental Biology 208(17): 3331-3339. ISSN: 0022-0949.
NAL Call Number: 442.8 B77
Descriptors: reptiles, American alligator, Alligator mississippiensis, terrestrial locomotion, does not constrain, venous return.
Overgaard, J., H. Gesser, and T. Wang (2007). Tribute to P. L. Lutz: Cardiac performance and cardiovascular regulation during anoxia/hypoxia in freshwater turtles. Journal of Experimental Biology 210(Pt 10): 1687-1699. ISSN: 0022-0949.
NAL Call Number: 442.8 B77
Abstract: Freshwater turtles overwintering in ice-covered ponds in North America may be exposed to prolonged anoxia, and survive this hostile environment by metabolic depression. Here, we review their cardiovascular function and regulation, with particular emphasis on the factors limiting cardiac performance. The pronounced anoxia tolerance of the turtle heart is based on the ability to match energy consumption with the low anaerobic ATP production during anoxia. Together with a well-developed temporal and spatial energy buffering by creatine kinase, this allows for cellular energy charge to remain high during anoxia. Furthermore, the turtle heart is well adapted to handle the adverse effects of free phosphate arising when phosphocreatine stores are used. Anoxia causes tenfold reductions in heart rate and blood flows that match the metabolic depression, and blood pressure is largely maintained through increased systemic vascular resistance. Depression of the heart rate is not driven by the autonomic nervous system and seems to arise from direct effects of oxygen lack and the associated hyperkalaemia and acidosis on the cardiac pacemaker. These intra- and extracellular changes also affect cardiac contractility, and both acidosis and hyperkalaemia severely depress cardiac contractility. However, increased levels of adrenaline and calcium may, at least partially, salvage cardiac function under prolonged periods of anoxia.
Descriptors: reptiles, freshwater turtles, cardiac performance, cardiovascular regulation, anoxia, hypoxia, heart, blood flow.
Overgaard, J., J.A. Stecyk, A.P. Farrell, and T. Wang (2002). Adrenergic control of the cardiovascular system in the turtle Trachemys scripta. Journal of Experimental Biology 205(Pt 21): 3335-3345. ISSN: 0022-0949.
NAL Call Number: 442.8 B77
Abstract: Freshwater turtles, Trachemys scripta, like all non-crocodilian reptiles, are able to shunt blood between the pulmonary and systemic circulations owing to their undivided ventricle. The prevailing hypothesis is that the ratio of pulmonary and systemic resistances is the primary determinant of cardiac shunting in turtles. In the present study, we have examined the adrenergic influences on vascular resistances in the pulmonary and systemic circulations and the associated effects on cardiac shunts in turtles. To achieve this objective, systemic blood flow and pressures and pulmonary blood flow and pressures were measured simultaneously in anaesthetised turtles during bolus injections of alpha- and beta-adrenergic agonists and antagonists. Total cardiac output, systemic vascular resistance, pulmonary vascular resistance, heart rate and cardiac stroke volume were derived from these measurements. Anaesthetised turtles showed cardiovascular characteristics that were similar to those of non-apnoeic non-anaesthetised turtles, because anaesthesia blocked the cholinergically mediated constriction of the pulmonary artery that is normally associated with apnoea. As a result, the anaesthetised turtles exhibited a large net left-to-right shunt, and the adrenergic responses could be observed without confounding changes resulting from apnoea. Potent alpha-adrenergic vasoconstriction and weaker beta-adrenergic vasodilation were discovered in the systemic circulation. Modest beta-adrenergic vasodilation and possible weak alpha-adrenergic vasodilation were discovered in the pulmonary circulation. This adrenergically mediated vasoactivity produced the largest range of cardiac shunts observed so far in turtles. Regression analysis revealed that 97% of the variability in the cardiac shunts could be accounted for by the ratio of the pulmonary and systemic resistances. Thus, we conclude that, independent of whether the pulmonary vascular resistance is modulated (as during apnoea) or the systemic resistance is modulated with adrenergic mechanisms (as shown here), the consequences on the cardiac shunt patterns are the same because they are determined primarily by the ratios of the pulmonary and systemic resistance.
Descriptors: reptiles, freshwater turtles, Trachemys scripta, cardiovascular system, andrenergic control, blood, cardiac shunts, undivided ventricle, cardiac output, stroke volume, heart rate.
Pejrilova, S., Z. Knotkova, Z. Knotek, and V. Vrbas (2004). Age-related changes of the haematological profile in green iguana (Iguana iguana rhinolopha). Acta Veterinaria Brno 73(3): 305-312. ISSN: 0001-7213.
NAL Call Number: SF604.B7
Descriptors: reptiles, green iguana, Iguana iguana rhinolopha, hematological profile, age related changes, blood sample taking, red blood cell counts, white blood cell counts, hemoglobin concentration, mean corpuscular volume.
Pendl, H. (2006). Morphologic changes in red blood cells of brids [birds] and reptiles and their interpretation. Israel Journal of Veterinary Medicine 61(1): 2-11. ISSN: 0334-9152.
NAL Call Number: 41.8 R25
Descriptors: reptiles, red blood cells, morphologic changes, birds, reptiles, interpretation, packed cell volume.
Porges, S.W., T.C. Riniolo, T. McBride, and B. Campbell (2003). Heart rate and respiration in reptiles: contrasts between a sit-and-wait predator and an intensive forager. Brain and Cognition 52(1): 88-96. ISSN: print: 0278-2626; online: 1090-2147.
Abstract: The current study investigated respiration and heart rate in two species of reptiles with distinct behavioral strategies: (1) the Sudan plated lizard (Gerrhosaurus major), a sit-and-wait predator; and (2) the Savanna monitor (Varanus exanthematicus), an intensive forager. It was hypothesized that (a) the plated lizard would not express respiratory sinus arrhythmia, and (b) the monitor, a reptile with behavioral and physiological characteristics similar to mammals, might express respiratory sinus arrhythmia, a pattern previously observed only in mammals. The data demonstrated that although there were strong vagal influences on the heart, respiratory activity was not manifested in the heart rate pattern of the plated lizards. In contrast, the monitor exhibited a reliable ventilatory influence on the heart rate pattern, although the pattern differed from the respiratory sinus arrhythmia observed in mammals. Consistent with the Polyvagal Theory (), the vagal control of the reptilian heart in both species appears to be mediated through the phylogenetically older unmyelinated system, a system that evolved to support metabolic conservation and not social behavior.
Descriptors: reptiles, Sudan plated lizard (Gerrhosaurus major), Savanna monitor (Varanus exanthematicus), heart rate, respiration, sinus arrhythmia, heart rate pattern, vagal control.
Sano Martins, I.S., Z. Dabrowski, Z. Tabarowski, E. Witkowska Pelc, D.D. Spadacci Morena, and K. Spodaryk (2002). Haematopoiesis and a new mechanism for the release of mature blood cells from the bone marrow into the circulation in snakes (Ophidia). Cell and Tissue Research 310(1): 67-75. ISSN: 0302-766X.
NAL Call Number: QH581.A1Z4
Abstract: This is the first description of haematopoiesis in snakes. Studies were carried out on the following species belonging to Ophidia: Bothrops jararaca, Bothrops jararacusu, Waglerophis merremii, Elaphe taeniura taeniura, Boa constrictor,and Python reticulatus. Smears of the peripheral blood and histological preparations from the vertebrae, ribs, liver, and spleen were studied under a light and electron microscope. Myeloid cells were present in the following locations in the vertebrae: the neural spine, zygoapophysial processes, floor of the neural canal, lacunae in the bodies of vertebrae and also inside the ribs. Although the vascular system was well developed, especially around the ribs, vessels inside the marrow cavities were scarce, both in the ribs and elsewhere where haematopoiesis was found. Venous sinuses were well developed in the vertebrae and in the rib regions from their costal head towards the middle area. They consisted of one layer of fine endothelial cells. Mature cells in the process of migration into the general circulation were only sporadically encountered when venous sinuses were studied on perfusion-fixed specimens. In contrast, almost every sinus venosus contained protrusions directed towards the lumen, filled mostly with mature and immature blood cells. Various stages of their formation were seen in the cross sections of venous sinuses ranging from small, newly formed to large, elongated ones, filled with many fully developed and some maturing blood cells. In many cases the apices of the protrusions were ruptured, and mature blood cells, as well as a few immature ones, were seen in their vicinity. This observation led us to a new hypothesis that blood cells are released from the extravascular space into the lumen of venous sinuses. In snakes, these cells are released into the systemic circulation mainly via the rupture of protrusions filled with mature blood cells and, to a lesser degree, by transcytosis as known in mammals. In the spleens from young specimens, 1-2 foci of haematopoiesis were encountered where lymphopoiesis predominated. Haematopoiesis was not detected in the liver.
Descriptors: reptiles, snakes, hematopoiesis, mature blood cells, bone marrow, new mechanism, peripheral blood smears, myeloid cells.
Santos, A.L.Q., T.S. Malta, A.V. Mundim, J.R.F. Alves Junior, and S.F.M. Carvalho (2005). Variacao dos constituintes bioquimicos sanguineos de Tartarguas-da-Amazonia (Podocnemis expansa, Schweigger - 1812) (Testudinata) mantidas em criatorio comercial. [Blood biochemistry rates of South American river turtle (Podocnemis expansa, Schweigger - 1812) (Testudinata) bred in captivity.]. Archives of Veterinary Science 10(3): 1-8. ISSN: 1517-784X.
Descriptors: reptiles, South American river turtle, Podocnemis expansa, blood biochemistry rates, bred in captivity.
Language of Text: Portuguese; Summary in English and Portuguese.
Seebacher, F. and C.E. Franklin (2005). Cardiovascular mechanisms during thermoregulation in reptiles. In: Animals and Environments: Proceedings of the Third International Conference of Comparative Physiology and Biochemistry,August 7, 2004-August 13, 2004, KwaZulu-Natal, South Africa, International Congress Series, 0531-5131, Elsevier: Amsterdam, p. 242-249. ISBN: 0444517634.
NAL Call Number: QP82 .I58 2004
Descriptors: reptiles, thermoregulation, cardiovascular mechanisms.
Seymour, R.S. and J.O. Arndt (2004). Independent effects of heart-head distance and caudal blood pooling on blood pressure regulation in aquatic and terrestrial snakes. Journal of Experimental Biology. 207(Pt 8): 1305-1311. ISSN: 0022-0949.
NAL Call Number: 442.8 B77
Abstract: Changes in orientation in a gravitational field markedly alter the patterns of blood pressure and flow in animals, especially tall or long ones such as giraffes or snakes. Vertical orientation tends to reduce blood flow and pressure in the head for two major reasons. First, the increased vertical blood column above the heart creates a gravitational hydrostatic pressure against which the heart must work. Second, expansion of dependent vessels in the lower extremities causes blood pooling and reduces return of venous blood to the heart, thereby lowering flow and pressure. For most animals, it is difficult to separate these two effects, but snakes offer the possibility of bending the animal in the region of the heart and manipulating the two ends of the body independently. We studied baroregulatory responses in terrestrial pythons (Liasis fuscus) and aquatic file snakes (Acrochordus arafurae) by tilting only the front or rear parts and then the whole animal. Changes in head blood pressure during partial tilts added up to the change during full tilt. The vertical distance to the head had twice as much influence on head blood pressure than did blood pooling in the pythons and four times as much in file snakes. This accounts for the cephalad location of the heart in terrestrial species compared with aquatic ones.
Descriptors: reptiles, snakes, heart-head distance, caudal blood pooling, blood pressure regulation, gravitational field, head blood pressure.
Silva, E.O., J.P. Diniz, S. Alberio, R. Lainson, W. de Souza, and R.A. DaMatta (2004). Blood monocyte alteration caused by a hematozoan infection in the lizard Ameiva ameiva (Reptilia: Teiidae). Parasitology Research 93(6): 448-456. ISSN: 0932-0113.
NAL Call Number: QL757.P377
Abstract: Although hematozoa have been described from many different host species, little is known about the infection and its relationship to the physiology of the host. We studied a hematozoan, regarded as a species of Lainsonia Landau, 1973 (Lankestereliidae), which infects the monocytes of the lizard Ameiva ameiva. The infected animals show a huge monocytosis and morphological changes in the monocytes. Ultrastructurally, the parasite has an apical complex, dense bodies, electron lucent structures, plasma membrane projections and folding which may be involved with nutrition. The parasite occupies a parasitophorous vacuole (PV) exhibiting high electron density at its membrane. Mitochondria and the Golgi complex of the monocytes were concentrated around the PV, and the cytoplasm was totally occupied by a vimentin type of intermediate filament radiating from (or to) the cytosolic surface of the PV. Vimentin was identified by diameter measurement, immunofluorescence and immunoelectron microscopy. These observations indicate that this infection alters the physiological state of the host and suggest that this parasite has the ability to modify monocyte vimentin assembly.
Descriptors: reptiles, lizard, Ameiva ameiva, parasites, hematozoan, lizard, blood monocyte, alteration, infection, monocytosis.
Skovgaard, N., A.S. Abe, D.V. Andrade, and T. Wang (2005). Hypoxic pulmonary vasoconstriction in reptiles: a comparative study of four species with different lung structures and pulmonary blood pressures. American Journal of Physiology. Regulatory, Integrative and Comparative Physiology 289(5): R1280-R1288. ISSN: print: 0363-6119; online: 1522-1490.
Abstract: Low O2 levels in the lungs of birds and mammals cause constriction of the pulmonary vasculature that elevates resistance to pulmonary blood flow and increases pulmonary blood pressure. This hypoxic pulmonary vasoconstriction (HPV) diverts pulmonary blood flow from poorly ventilated and hypoxic areas of the lung to more well-ventilated parts and is considered important for the local matching of ventilation to blood perfusion. In the present study, the effects of acute hypoxia on pulmonary and systemic blood flows and pressures were measured in four species of anesthetized reptiles with diverse lung structures and heart morphologies: varanid lizards (Varanus exanthematicus), caimans (Caiman latirostris), rattlesnakes (Crotalus durissus), and tegu lizards (Tupinambis merianae). As previously shown in turtles, hypoxia causes a reversible constriction of the pulmonary vasculature in varanids and caimans, decreasing pulmonary vascular conductance by 37 and 31%, respectively. These three species possess complex multicameral lungs, and it is likely that HPV would aid to secure ventilation-perfusion homogeneity. There was no HPV in rattlesnakes, which have structurally simple lungs where local ventilation-perfusion inhomogeneities are less likely to occur. However, tegu lizards, which also have simple unicameral lungs, did exhibit HPV, decreasing pulmonary vascular conductance by 32%, albeit at a lower threshold than varanids and caimans (6.2 kPa oxygen in inspired air vs. 8.2 and 13.9 kPa, respectively). Although these observations suggest that HPV is more pronounced in species with complex lungs and functionally divided hearts, it is also clear that other components are involved.
Descriptors: lizards, Varanus exanthematicus, Tupinambis merianae, caimans, Caiman latirostris, rattlesnakes, Crotalus durissus, lung structures, hypoxic pulmonary vasoconstriction, blood pressures, 02 levels, HPV.
Skovgaard, N., G. Galli, A. Abe, E.W. Taylor, and T. Wang (2005). The role of nitric oxide in regulation of the cardiovascular system in reptiles. Comparative Biochemistry and Physiology. Part A, Molecular and Integrative Physiology 142(2): 205-214. ISSN: 1095-6433.
Abstract: The roles that nitric oxide (NO) plays in the cardiovascular system of reptiles are reviewed, with particular emphasis on its effects on central vascular blood flows in the systemic and pulmonary circulations. New data is presented that describes the effects on hemodynamic variables in varanid lizards of exogenously administered NO via the nitric oxide donor sodium nitroprusside (SNP) and inhibition of nitric oxide synthase (NOS) by l-nitroarginine methyl ester (l-NAME). Furthermore, preliminary data on the effects of SNP on hemodynamic variables in the tegu lizard are presented. The findings are compared with previously published data from our laboratory on three other species of reptiles: pythons (), rattlesnakes () and turtles (). These five species of reptiles possess different combinations of division of the heart and structural complexity of the lungs. Comparison of their responses to NO donors and NOS inhibitors may reveal whether the potential contribution of NO to vascular tone correlates with pulmonary complexity and/or with blood pressure. All existing studies on reptiles have clearly established a potential role for NO in regulating vascular tone in the systemic circulation and NO may be important for maintaining basal systemic vascular tone in varanid lizards, pythons and turtles, through a continuous release of NO. In contrast, the pulmonary circulation is less responsive to NO donors or NOS inhibitors, and it was only in pythons and varanid lizards that the lungs responded to SNP. Both species have a functionally separated heart, so it is possible that NO may exert a larger role in species with low pulmonary blood pressures, irrespective of lung complexity.
Descriptors: reptiles, nitric oxide, NO, cardiovascular system, roles, regulation, systemic circulation, pulmonary circulation, blood pressure.
Skovgaard, N., D.E. Warren, D.C. Jackson, and T. Wang (2005). Endothelin-1 causes systemic vasodilatation in anaesthetised turtles (Trachemys scripta) through activation of ETB-receptors. Journal of Experimental Biology. 208(Pt 19): 3739-3746. ISSN: 0022-0949.
NAL Call Number: 442.8 B77
Abstract: The effects of endothelin-1 (ET-1) on systemic and pulmonary circulation were investigated in anaesthetised freshwater turtles (Trachemys scripta) instrumented with arterial catheters and blood flow probes. Bolus intra-arterial injections of ET-1 (0.4-400 pmol kg(-1)) caused a dose-dependent systemic vasodilatation that was associated with a decrease in systemic pressure (P(sys)) and a rise in systemic blood flow (Q(sys)), causing systemic conductance (G(sys)) to increase. ET-1 had no significant effects on the pulmonary vasculature, heart rate (fh) or total stroke volume (Vs(tot)). This response differs markedly from mammals, where ET-1 causes an initial vasodilatation that is followed by a pronounced pressor response. In mammals, the initial dilatation is caused by stimulation of ET(B)-receptors, while the subsequent constriction is mediated by ET(A)-receptors. In the turtles, infusion of the ET(B)-receptor agonist BQ-3020 (150 pmol kg(-1)) elicited haemodynamic changes that were similar to those of ET-1, and the effects of ET-1 were not affected by the ET(A)-antagonist BQ-610 (0.15 micromol kg(-1)). Conversely, all effects of ET-1 were virtually abolished after specific ET(B)-receptor blockade with the ET(B)-antagonist BQ-788 (0.15 micromol kg(-1)). The subsequent treatment with the general ET-receptor antagonist tezosentan (15.4 micromol kg(-1)) did not produce effects that differed from the treatment with ET(B)-antagonist, and the blockade of ET-1 responses persisted. This present study indicates, therefore, that ET(B)-receptors are responsible for the majority of the cardiovascular responses to ET-1 in Trachemys.
Descriptors: turtles, Trachemys scripta, anesthetised, systemic vasodilatation, blood flow, endothelin-1, pulmonary circulation, ETB recptors.
Skovgaard, N. and T. Wang (2006). Local control of pulmonary blood flow and lung structure in reptiles: implications for ventilation perfusion matching. Respiratory Physiology and Neurobiology 154(1-2): 107-117. ISSN: 1569-9048.
NAL Call Number: QP121.A1 R4
Descriptors: reptiles, pulmonary blood flow, local control, lung structure, ventilation perfusion matching, implications, chambered lungs.
Soslau, G., P.J. Prest, R. Class, R. George, F. Paladino, and G. Violetta (2005). Comparison of sea turtle thrombocyte aggregation to human platelet aggregation in whole blood. Comparative Biochemistry and Physiology. Part B, Biochemistry and Molecular Biology 142(3): 353-360. ISSN: 1096-4959.
Abstract: The endangered sea turtles are living "fossils" that afford us an opportunity to study the hemostatic process as it likely existed millions of years ago. There are essentially no data about turtle thrombocyte aggregation prior to our studies. Thrombocytes are nucleated cells that serve the same hemostatic functions as the anucleated mammalian platelet. Sea turtle thrombocytes aggregate in response to collagen and beta-thrombin. Ristocetin induces an agglutination/aggregation response indicating the presence of a von Willebrand-like receptor, GPIb, found in all mammalian platelets. Samples treated with alpha-thrombin plus gamma-thrombin followed by ristocetin results in a rapid, stronger response than ristocetin alone. These responses are inhibited by the RGDS peptide that blocks fibrinogen cross-linking of mammalian platelets via the fibrinogen receptor, GPIIb/IIIa. Three platelet-like proteins, GPIb, GPIIb/IIIa and P-selection are detected in sea turtle thrombocytes by fluorescence activated cell sorting. Turtle thrombocytes do not respond to ADP, epinephrine, serotonin, thromboxane A2 mimetic, U46619, trypsin, or alpha-thrombin and gamma-thrombin added alone. Comparison of hemostasis in sea turtles to other vertebrates could provide a framework for understanding the structure/function and evolution of these pathways and their individual components.
Descriptors: sea turtle, thrombocyte aggregation, human platelet aggregation, whole blood, comparison, hemostatic functions.
Soslau, G., D.A. Morgan, R. Class, F.V. Paladino, R. George, B. Whitaker, G.C. Violetta, S.J. Goldenberg, and J.R. Spotila (2003). Coagulatin and platelet aggregation in sea turtles. NOAA Technical Memorandum NMFS SEFSC 503: 306-307.
Descriptors: reptiles, sea turtles, coagulation, platelet aggregation, cardiovascular, blood.
Southwood, A.L., C.A. Darveau, and D.R. Jones (2003). Metabolic and cardiovascular adjustments of juvenile green turtles to seasonal changes in temperature and photoperiod. Journal of Experimental Biology 206(24): 4521-4531. ISSN: 0022-0949.
NAL Call Number: 442.8 B77
Descriptors: repetiles, juvenile green turtles, temperature changes, photoperiod, metabolic, cardiovascular, adjustments.
Stawski, C.Y., G.C. Grigg, D.T. Booth, and L.A. Beard (2006). Temperature and the respiratory properties of whole blood in two reptiles, Pogona barbata and Emydura signata. Comparative Biochemistry and Physiology. Part A, Molecular and Integrative Physiology 143(2): 173-183. ISSN: 1095-6433.
Abstract: We investigated the capacity of two reptiles, an agamid lizard Pogona barbata and a chelid turtle Emydura signata, to compensate for the effects of temperature by making changes in their whole blood respiratory properties. This was accomplished by measuring the P50 (at 10, 20 and 30 degrees C), hematocrit (Hct), haemoglobin concentration ([Hb]) and mean cell haemoglobin concentration (MCHC) in field acclimatised and laboratory acclimated individuals. The acute effect of temperature on P50 in P. barbata, expressed as heat of oxygenation (deltaH), ranged from -16.8+/-1.84 to -28.5+/-2.73 kJ/mole. P50 of field acclimatised P. barbata increased significantly from early spring to summer at the test temperatures of 20 degrees C (43.1+/-1.2 to 48.8+/-2.1 mmHg) and 30 degrees C (54.7+/-1.2 to 65.2+/-2.3 mmHg), but showed no acclimation under laboratory conditions. For E. signata, deltaH ranged from -31.1+/-6.32 to -48.2+/-3.59 kJ/mole. Field acclimatisation and laboratory acclimation of P50 did not occur. However, in E. signata, there was a significant increase in [Hb] and MCHC from early spring to summer in turtles collected from the wild (1.0+/-0.1 to 1.7+/-0.2 mmol/L and 4.0+/-0.3 to 6.7+/-0.7 mmol/L, respectively).
Descriptors: reptiles, turtle, Emydura signata, lizard, Pogona barbata, temperature, respiratory properties, whole blood, acclimation.
Stecyk, J.A. and A.P. Farrell (2007). Effects of extracellular changes on spontaneous heart rate of normoxia- and anoxia-acclimated turtles (Trachemys scripta). Journal of Experimental Biology 210(Pt 3): 421-431. ISSN: 0022-0949.
NAL Call Number: 442.8 B77
Abstract: Heart rate (f(H)) of the anoxia-tolerant freshwater turtle (Trachemys scripta) during prolonged anoxia exposure is 2.5- to 5-times lower than the normoxic rate, but whether alterations in blood composition that accompany prolonged anoxia contribute to this bradycardia is unknown. We examined how temperature acclimation, oxygen deprivation, acidosis, hyperkalemia, hypercalcemia and adrenaline affect chronotropy in the turtle myocardium. We monitored spontaneous contraction rates of right-atrial preparations obtained from 21 degrees C- and 5 degrees C-acclimated turtles that had been exposed to either normoxia or anoxia (6 h at 21 degrees C; 2 weeks at 5 degrees C). Sequential exposures to saline solutions were designed to mimic, in a step-wise manner, the shift from a normoxic to anoxic extracellular condition (for normoxia-acclimated preparations) or the reverse (for anoxia-acclimated preparations). Our results clearly show that prolonged anoxia exposure re-sets the intrinsic f(H) of turtles at both temperatures, with reductions in intrinsic f(H) in the range of 25%-53% compared with normoxia. This intrinsic change would contribute to the bradycardia observed with prolonged anoxia. Further, we found negative chronotropic effects of extracellular anoxia, acidosis and hyperkalemia, and positive chronotropic effects of hypercalcemia and adrenaline. The exact nature of these extracellular effects depended, however, on the acclimation temperature and the prior exposure of the animal to anoxia. With normoxia-acclimated preparations at 21 degrees C, combined anoxia and acidosis (pH reduced from approximately 7.8 to approximately 7.2) significantly reduced spontaneous f(H) by 22% and subsequent exposure to hyperkalemia (3.5 mmol l(-1)K(+)) further decreased f(H). These negative chronotropic effects were ameliorated by increasing the adrenaline concentration from the tonic level of 1 nmol l(-1) to 60 nmol l(-1). However, in anoxia-acclimated preparations at 21 degrees C, anoxia alone inhibited f(H) (by approximately 30%). This negative chronotropic effect was counteracted by both hypercalcemia (6 mmol l(-1) Ca(2+)) and adrenaline (60 nmol l(-1)). At 5 degrees C, only the combination of anoxia, acidosis (pH reduced from approximately 8.0 to approximately 7.5) and hyperkalemia (3.5 mmol l(-1) K(+)) significantly reduced spontaneous f(H) (by 23%) with preparations from normoxia-acclimated turtles. This negative chronotropic effect was fully reversed by hypercalcemia (10 mmol l(-1) Ca(2+)). By contrast, spontaneous f(H) of anoxia-acclimated preparations at 5 degrees C was not affected by any of the extracellular changes. We conclude that prior temperature and anoxia experiences are central to determining f(H) during prolonged anoxia in Trachemys scripta both as a result of the re-setting of pacemaker rhythm and through the potential influence of extracellular changes.
Descriptors: reptiles, freshwater turtle, Trachemys scripta, extracellular changes, effect, spontaneous heart rate, normoxia, anoxia, bradycardia.
Toney, V.I. and D.C. Jackson (2003). Cardiovascular effects of graded hypoxia and graded acidosis on the myocardium of the western painted turtle. FASEB Journal 17(4-5): Abstract No. 313.5. ISSN: 0892-6638.
NAL Call Number: QH301.F3
Descriptors: reptiles, painted turtle, graded hypoxia, acidosis myocardium, cardiovascular, effects, meeting.
Notes: Meeting Information: FASEB Meeting on Experimental Biology: Translating the Genome, San Diego, CA, USA; April 11-15, 2003.
Toney, V.I. and D.C. Jackson (2002). Cardiovascular effects of graded hypoxia on the myocardium of the western painted turtle. FASEB Journal 16(5): A887. ISSN: 0892-6638.
NAL Call Number: QH301.F3
Descriptors: reptiles, painted turtle, graded hypoxia, effects, myocardium, cardiovascular, effects, meeting abstracts.
Notes: Meeting Information: Annual Meeting of Professional Research Scientists on Experimental Biology, New Orleans, Louisiana, USA; April 20-24, 2002.
Voituron, Y., J.M. Storey, C. Grenot, and K.B. Storey (2002). Freezing survival, body ice content and blood composition of the freeze-tolerant European common lizard, Lacerta vivipara. Journal of Comparative Physiology. B, Biochemical, Systemic, and Environmental Physiology 172(1): 71-76. ISSN: print: 0174-1578; online: 1432-136X.
NAL Call Number: QP33.J681
Abstract: To investigate the freeze tolerance of the European common lizard, Lacerta vivipara, we froze 17 individuals to body temperatures as low as -4 degrees C under controlled laboratory conditions. The data show that this species tolerates the freezing of 50% of total body water and can survive freezing exposures of at least 24-h duration. Currently, this represents the best known development of freeze tolerance among squamate reptiles. Freezing stimulated a significant increase in blood glucose levels (16.15+/- 1.73 micromol x ml(-1) for controls versus 25.06 +/- 2.92 micromol x ml(-1) after thawing) but this increase had no significant effect on serum osmolality which was unchanged between control and freeze-exposed lizards (506.0 +/- 23.8 mosmol x l(-1) versus 501.0 +/- 25.3 mosmol x l(-1), respectively). Tests that assessed the possible presence of antifreeze proteins in lizard blood were negative. Recovery at 5 degrees C after freezing was assessed by measurements of the mean time for the return of breathing (5.9 +/- 0.5 h) and of the righting reflex (44.8 +/- 4.5 h). Because this species hibernates in wet substrates inoculative freezing may frequently occur in nature and the substantial freeze tolerance of this lizard should play a key role in its winter survival.
Descriptors: reptiles, European common lizard, Lacerta vivipara, freezing survival, body ice, blood composition, freeze tolerant, serum osmolality, breathing.
Zaar, M., E. Larsen, and T. Wang (2004). Hysteresis of heart rate and heat exchange of fasting and postprandial savannah monitor lizards (Varanus exanthematicus). Comparative Biochemistry and Physiology. Part A, Molecular and Integrative Physiology 137(4): 675-682. ISSN: 1095-6433.
Abstract: Reptiles are ectothermic, but regulate body temperatures (T(b)) by behavioural and physiological means. Body temperature has profound effects on virtually all physiological functions. It is well known that heating occurs faster than cooling, which seems to correlate with changes in cutaneous perfusion. Increased cutaneous perfusion, and hence elevated cardiac output, during heating is reflected in an increased heart rate (f(H)), and f(H), at a given T(b), is normally higher during heating compared to cooling ('hysteresis of heart rate'). Digestion is associated with an increased metabolic rate. This is associated with an elevated f(H) and many species of reptiles also exhibited a behavioural selection of higher T(b) during digestion. Here, we examine whether digestion affects the rate of heating and cooling as well as the hysteresis of heart rate in savannah monitor lizards (Varanus exanthematicus). Fasting lizards were studied after 5 days of food deprivation while digesting lizards were studied approximately 24 h after ingesting dead mice that equalled 10% of their body mass. Heart rate was measured while T(b) increased from 28 to 38 degrees C under a heat lamp and while T(b) decreased during a subsequent cooling phase. The lizards exhibited hysteresis of heart rate, and heating occurred faster than cooling. Feeding led to an increased f(H) (approximately 20 min(-1) irrespective of T(b)), but did not affect the rate of temperature change during heating or cooling. Therefore, it is likely that the increased blood flows during digestion are distributed exclusively to visceral organs and that the thermal conductance remains unaffected by the elevated metabolic rate during digestion.
Descriptors: reptiles, savannah monitor lizards, Varanus exanthematicus, heart rate, heat exchange, fasting, post prandial, body temperature, digestion, cardiac output, heating, cooling.