Hostname: page-component-8448b6f56d-sxzjt Total loading time: 0 Render date: 2024-04-19T16:53:24.464Z Has data issue: false hasContentIssue false

Gluconeogenesis in foetal, suckling and weaned lambs: the effect of glucagon

Published online by Cambridge University Press:  27 March 2009

P. M. J. Savan
Affiliation:
Department of Physiology and Biochemistry, The University, Whiteknights, Reading, RG6 2AJ
D. A. L. Shepherd
Affiliation:
Department of Physiology and Biochemistry, The University, Whiteknights, Reading, RG6 2AJ

Summary

The effect of glucagon on the rate of glucose production in the presence of alanine, of lactate and of propionate has been studied in isolated perfused livers obtained from foetal, suckling and weaned lambs.

Glucose utilization occurred in foetal livers in the absence of glucagon whereas addition of glucagon resulted in a net production of glucose from the three substrates. In livers from suckling and weaned lambs addition of glucagon was not essential for glucose production to occur and the stimulation of gluconeogenesis by added glucagon was less evident in the older lambs. The effect of glucagon was not dependent on changes in the rate of substrate uptake.

It is concluded that gluconeogenesis will be induced by glucagon in foetal lambs when their mothers are severely undernourished, and that placentally derived lactate could contribute up to 90% of the glucose synthesized.

Type
Research Article
Copyright
Copyright © Cambridge University Press 1986

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

REFERENCES

Agricultural Research Council (1965). The Nutrient Requirements of Farm Livestock, No. 2. Ruminants. London: Agricultural Research Council.Google Scholar
Bergman, E. N. (1983). The pools of cellular nutrients: glucose. In Dynamic Biochemistry of Animal Production (ed. Riis, P. M.), pp. 173199. Amsterdam: Elsevier.Google Scholar
Brockman, R. P., Bergman, E. N., Joo, P. K. & Manns, J. G. (1975). Effects of glucagon and insulin on net hepatic metabolism of glucose precursors in sheep. American Journal of Physiology 229, 13441350.Google Scholar
Brockman, R. P. & Manns, J. G. (1974). Effects of glucagon on activities of hepatic enzymes in sheep. Cornell Veterinarian 64, 217224.Google ScholarPubMed
Edwards, E. M., Dhand, U. K., Jeacock, M. K. & Shepherd, D. A. L. (1975). Activities of enzymes concerned with pyruvate and oxaloacetate metabolism in the heart and liver of developing sheep. Biochimica et Biophysica Acta 399, 217227.Google Scholar
Girard, J. R., Ferre, P., Gilbert, M., Kervran, A., Assan, R. & Marliss, E. B. (1977). Fetal metabolic response to maternal fasting in the rat. American Journal of Physiology 232, E456E463.Google Scholar
Hatfield, G. M., Joyce, J., Jeacock, M. K. & Shepherd, D. A. L. (1984). The irreversible loss of alanine and of glycine in fetal and suckling lambs. British Journal of Nutrition 52, 529543.CrossRefGoogle Scholar
Hay, W. W., Sparks, J. W., Quissell, B. J., Battaglia, F. C. & Meschia, G. (1981). Simultaneous measurements of umbilical uptake, fetal utilization rate, and fetal turnover rate of glucose. American Journal of Physiology 240, E662E668.Google Scholar
Hay, W. W., Sparks, J. W., Wilkening, R. B., Battaglia, F. C. & Meschia, G. (1984). Fetal glucose uptake and utilization as functions of maternal glucose concentration. American Journal of Physiology 246, E237E242.Google Scholar
Kitts, D. D. & Krishnamurti, C. R. (1982). Substrate metabolism and interrelationships in the ovine fetus in utero. Canadian Journal of Animal Science 62, 397408.CrossRefGoogle Scholar
Lemons, J. A. III, Adcock, E. W., Jones, M. D. Jr, Naughton, M. A., Meschia, G. & Battaglia, F. C. (1976). Umbilical uptake of amino acids in the unstressed fetal lamb. Journal of Clinical Investigation 58, 14281434.CrossRefGoogle ScholarPubMed
Lindsay, D. B. (1978). Gluconeogenesis in ruminants. Biochemical Society Transactions 6, 11521156.CrossRefGoogle ScholarPubMed
McDowell, G. H. (1983). Hormonal control of glucose homeostasis in ruminants. Proceedings of the Nutrition Society 42, 149167.Google Scholar
Ministry of Agriculture, Fisheries and Food (1975). Energy allowances and feeding systems for ruminants. Technical Bulletin No. 33. London: H.M.S.O.Google Scholar
Philipps, A., Dubin, J. W., Matty, P. J. & Raye, J. R. (1983). Influence of exogenous glucagon on fetal glucose metabolism and ketone production. Pediatric Research 17, 5156.CrossRefGoogle ScholarPubMed
Prior, R. L. (1980). Glucose and lactate metabolism in vivo in ovine fetus. American Journal of Physiology 239, E208E214.Google ScholarPubMed
Prior, R. L. (1982). Gluconeogenesis in the ruminant fetus: evaluation of conflicting evidence from radiotracer and other experimental techniques. Federation Proceedings 41, 117122.Google Scholar
Rattenbury, J. M., Jeacock, M. K. & Shepherd, D. A. L. (1980). Urea synthesis in the liver and kidney of developing sheep. Biochimica et Biophysica Acta 630, 210219.Google Scholar
Richardson, T. C., Jeacock, M. K. & Shepherd, D. A. L. (1982). The effect of implantation of anabolic steroids into suckling and ruminating lambs on the metabolism of alanine in livers perfused in the presence or absence of volatile fatty acids. Journal of Agricultural Science, Cambridge 99, 391401.Google Scholar
Savan, P. M. J., Jeacock, M. K. & Shepherd, D. A. L. (1976). Hepatic gluconeogenesis in foetal and suckling lambs. Proceedings of the Nutrition Society 35, 30A.Google ScholarPubMed
Savan, P. M. J., Jeacock, M. K. & Shepherd, D. A. L. (1979). The fate of amino acids in isolated perfused livers of developing sheep. British Journal of Nutrition 42, 467476.CrossRefGoogle ScholarPubMed
Schreiner, R. L., Lemons, J. A. & Gresham, E. L. (1981). Metabolic and hormonal response to chronic maternal fasting in the ewe. Annals of Nutrition Metabolism 25, 3847.CrossRefGoogle ScholarPubMed
Schreiner, R. L., Lemons, J. A., Moorehead, H., Bohnke, R. & Reyman, D. (1982). Effects of exogenou glucagon on concentrations of glucose, fructose and insulin in plasma of sheep fetus. Annals of Nutrition and Metabolism 26, 152161.Google Scholar
Sparks, J. W., Hay, W. W., Bonds, D., Meschia, G. & Battaglia, F. C. (1982). Simultaneous measurements of lactate turnover rate and umbilical lactate uptake in the fetal lamb. Journal of Clinical Investigation 70, 179192.Google Scholar
Van Schaftingen, E., Hue, L. & Hers, H-G. (1980). Control of the fructose 6-phosphate/fructose 1,6-bisphosphate cycle in isolated hepatocytes by glucose and glucagon. Biochemical Journal 192, 887895.Google Scholar
Warnes, D. M., Seamark, R. F. & Ballard, F. J. (1977 a). Metabolism of glucose, fructose and lactate in vivo in chronically cannulated foetuses and in suckling lambs. Biochemical Journal 162, 617626.Google Scholar
Warnes, D. M., Seamark, D. M. & Ballard, F. J. (1977 b). The appearance of gluconeogenesis at birth in sheep. Biochemical Journal 162, 627634.Google Scholar