Main Article Content

Abstract

The behavioral, physiological and biochemical response to low (2°C) and high (45°C) temperatures was studied in Uromastyx aegyptius. Twelve animals were divided into two experimental groups. A third control group was kept at 22 °C.  All animals in the cooling, warming, and control groups were allowed a period of 24 hours for adjustments at 22 °C.  Blood samples were collected from each animal when body temperature reached the corresponding levels. The results showed a significant (P<0.05) decrease in blood glucose and cholesterol levels during cooling (2°C). This reduction in extracellular fluid substrates reflects an increase in cellular uptake of these substrates. Warming (45°C) resulted in a significant  (P< 0.05) increase in total proteins, urea, and uric acid. These later changes could be attributed to an increase in the evaporative water loss, particularly due to the increased observed panting, and the associated reduction in plasma volume. There were no significant (P>0.05) changes in T3 and T4, during cooling nor during warming. The results of this study suggest augmentation of anaerobic metabolism of the U.aegyptius during cooling as evident by reduction in blood glucose levels. Furthermore, shift of glucose from the extracellular to the intracellular fluids demonstrates anticipation against potential freezing in order to protect the animal from intracellular freezing.

 

 

Keywords

Metabolism Temperature Behaviour Blood Constituents Plasma Uromastyx Lizard.

Article Details

References

  1. ARNOLD, E.N. 1986. A key and annotated checklist to the lizards and amphisbaenians of Arabia. Fauna of Saudi Arabia 8: 335-435.
  2. ARTISS, J.D. and ENTWISTLE, W.M. 1981.The application of a sensitive uricase-peroxidase couple reaction to a centrifugal fast analyser for the determination of uric acid. Clin Chim Acta.; 116(3):301-309.
  3. ABU-TARBOUSH, H. M., AL-JOHANY, A.M. and AL-SADOON, M.K. 1996. Proximate composition and fatty acids and cholestrol content of U.aegyptius’s meat (Uromastyx aegyptius Blanford 1874) at the end of winter and during spring. Journal of College of Agriculture of King Saud University. 8 : 79-92.
  4. AL-TUWAIJRI, A.S. 1987. Standard Biological Data. Human and Experimental animals. King Saud University Press, Riyadh, Saudi Arabia.
  5. ANONYMOUS 1989. The French consensus on cholesterol and dyslipoproteinemias. Administration Council of ARCOL. Rev. Prat.; 39(11): 972-974. Review. French.
  6. BARTHOLMEW, G.A. 1981. Physiological thermoregulation. In Biology of the reptilia. Vol. 12, Physiological ecology eds C. Gans and F. H. Pough). Academic press, New York. pp. 167-212
  7. BAUWENS, D. 1981. Survivorship during hibernation in the European common lizard, Lacerta vivipara. Copeia 1981: 741-744.
  8. CASE, T. J. 1976. Seasonal aspect of thermoregulatory behavior in the chuckawalla, Sauromalus obesus (Reptilia, Lacertilia, Iguanidae). Journal of Herpetology 10: 85-95.
  9. COSSINS, A. R., and BOWLER, K. 1987. Temperature biology of animals. Chapman & Hall, London.
  10. COSTANZO, J.P., GRENOT, C. and LEE, R.E.Jr. 1995. Supercooling ice inoculation and freeze tolerance in the European common lizard, Lacerta vivipara. Journal of Comparative Physiology B, 165: 238-244.
  11. DRUPT, F., PARIS, M., FRYDMAN, A., LECLERC, M. 1974. Plasma albumin assay by bromocresol green method: application to different automatic apparatus. Ann Pharm Fr. 32(5):249-256. French.
  12. DUNLAP, K.D. 1995. External and internal influences on indices of physiological stress: II. Seasonal and size related variations in blood composition in free-living lizards, Sceloporus occidentalis. Journal of Experimental Zoology 272: 85-94.
  13. FEDER, M.E. and HOFMANN, G.E. (1998). Evolutionary and ecological physiology of heat-shock proteins and the heat-shock response: comparative bibliography. Annual Review of Physiology 61: 243-282.
  14. FIRTH, B. T. and BELAN, I. 1998. Daily and seasonal rhythms in selected body temperature in the Australian lizard Tiliqua rugosa (Scincidae): Field and laboratory observations . Physiological Zoology 71: 303-311.
  15. FOSSATI, P. and PRENCIPE, L. 1982 Plasma triglycerides determined colorimetrically with an enzyme that produces hydrogen peroxide. Clinical Chemistry Oct; 28(10):2077-80.
  16. GEISER, F., FIRTH, B.T., and SIGMOUR, R. S. 1992. Poly-unsaturated dietary lipids lower the selected body temperature of a lizard. Journal of Comparative Physiology B, 162: 1-4.
  17. GRENOT, C., and HEULIN, B. 1990. Sur la palasticite ecophysiologique du lezard vivipare, Lacerta vivipara (Reptilia, Lacertidae). Bulletin of Society for Herpetology, France. 54: 1-22.
  18. GRIGG, G.C. and SEEBACHER, F. 1999. Field test of a paradigm: hysteresis of heart rate in thermoregulation by a free-ranging lizard (Pogona barbata). Proceeding of Royal Society London. B. Biological Science 266: 1291-1297.
  19. HAZEL, J. R. and PROSSER, C.L. 1974. Molecular mechanisms of temperature compensation in poikilotherms. Physiology Review 54: 620-677.
  20. HEW, C.L., SCOTT, G. K. and DAVIES, P.L. 1986. Molecular biology of antifreeze. In Living in the cold: Physiological and biochemical adaptations eds H. C. Heller., X.J. Musacchia and L.C.H. Wang Elsevier, New York. pp. 117-123.
  21. HUEY, R.B. 1982. Temperature, physiology and the ecology of reptiles. In Biology of the reptilia Vol. 12, Physiological ecology ed. F.H. Pough. Academic Press, London. pp. 26-90.
  22. LEE, R.E., and COSTANZO, J.P. 1993. Integrated physiological responses promoting anuran freeze tolerance. In Life in the cold III: ecological, physiological and molecular mechanisms eds C. Carey et. al. Westview Press, Boulder, Colarado. pp. 501-510.
  23. LEMOS-ESPINAL, J. A., and BALLINGER, R.E. 1992. Observations on the tolerance to freezing by the lizard, Sceloporus grammicus, from Iztaccihuattl volcano, Mexico. Herpetological Review 23: 8-9.
  24. LINDQUIST, S. 1986. The heat shock response. Annual Review of Biochemistry. 55:1151-1191.
  25. LOUW, G.N. and GIDEON, N. 1993. Physiological animal ecology. John Wiley & Sons Inc. New York.
  26. MORIMOTO, R.I. 1993. Cells in stress: transcriptional activation of heat shock genes. Science 259: 1409-1410.
  27. MORIMOTO, R.I., TISSIERES, A. and GEORGOPOLOUS, C. 1994. The biology of heat shock proteins and molecular chaperones. Cold Spring Harbor Laboratory Press, Plainview, NY.
  28. PATTON, C. J. and CROUCH, S.R. 1977. Spectrophotometric and kinetic investigation of Berthelot reaction for the determination of ammonia. Anal. Chem.; 49 (1-4): 464-469.
  29. PETERS, T. Jr. 1968. Proposals for standardization of total protein assays. Clinical Chemistry Dec; 14(12):1147-59.
  30. SINHA, A.K. and CHOUBEY, B.J. 1981. Seasonal changes in the thyroid gland of Indian spiny tailed, sand lizard, Uromastix hardwickii (Gray) male. Z. Mikrosk. Anat. Forsch. 95:72-80.
  31. STOREY, K.B. and STOREY, J. M. 1992. Natural freeze tolerance in ectothermic vertebrates. Annual Review of Physiology 54: 619-637.
  32. TRINDER, P. 1969. Determination of blood glucose using 4-amino phenazone as oxygen acceptor. Journal of Clinical Patholology.; Mar; 22(2):246.
  33. ULMASOV, K.A., SHAMMAKOV, S., KARAEV, K. and EVEGENEV, M.B. 1992. Heat shock proteins and thermoresistance in lizards. Proceeding of National Academy of Science. 89: 1666-1670.
  34. WHITE, F.N., and SOMERO, G. 1982. Acid-base regulation and phospholipid adaptation to temperature: Time course and physiological significance of modifying the milieu for protein function. Physiology Review 62: 40-90.
  35. WITHERS, P. C. 1992. Comparative Animal Physiology. Saunders College Publishing, New York.
  36. ZATESPINA, O.G., ULMASOV, K.A., BERESTEN, S.F., MOLODTSOV, V.B., RYBTSOV, S.A. and EVEGENEV, M.B. 2000. Thermotolerant desert lizards characteristically differ in terms of heat-shock system regulation. Journal of Experimental Biology, 203: 1017-1025.