Hostname: page-component-8448b6f56d-sxzjt Total loading time: 0 Render date: 2024-04-23T23:51:06.167Z Has data issue: false hasContentIssue false

Glutamate and glutamine metabolism in tissues of developing lambs

Published online by Cambridge University Press:  27 March 2009

Jennifer M. Pell
Affiliation:
Department of Physiology and Biochemistry, University of Reading, Whiteknights, Reading, RG6 2AJ
Julia Tooley
Affiliation:
Department of Physiology and Biochemistry, University of Reading, Whiteknights, Reading, RG6 2AJ
Marjorie K. Jeacock
Affiliation:
Department of Physiology and Biochemistry, University of Reading, Whiteknights, Reading, RG6 2AJ
D. A. L. Shepherd
Affiliation:
Department of Physiology and Biochemistry, University of Reading, Whiteknights, Reading, RG6 2AJ

Summary

The activities of glutamine synthetase, phosphate-dependent glutaminase, phosphate-independent glutaminase, glutamate dehydrogenase, γ-glutamyl transferase and glutamine-oxo-acid aminotransferase were assayed in liver, kidney cortex, brain (cerebral hemispheres), spleen, skeletal muscle and ileum obtained from lambs of 100–260 days conceptual age. A curve was fitted to each set of data relating enzyme activity and conceptual age.

In the ileum, glutaminase and γ-glutamyl transferase activities declined during development. Glutamine synthetase activity in the spleen increased markedly after birth, whereas glutamate dehydrogenase activity declined as rumen function was established. In the liver, glutamate dehydrogenase and glutamine synthetase activities were highest in suckling lambs and there was a gradual increase in hepatic γ-glutamyl transferase activity throughout the period studied. The activity of phosphate-dependent glutaminase was lowest in the kidney cortex of ruminating lambs but renal activities of glutamate dehydrogenase, phosphate-independent glutaminase, glutamine synthetase and γ-glutamyl transferase were highest in ruminating lambs. In skeletal muscle, a gradual increase in glutamine synthetase activity occurred after 180 days conceptual age, whereas there was no detectable glutaminase activity in ruminating lambs. In the brain, there was an increase in glutamate dehydrogenase, phosphatedependent glutaminase and glutamine synthetase activities during the foetal and early suckling periods, whereas γ-glutamyl transferase activity increased throughout the period studied.

Glutamine-oxo-acid aminotransferase activity was not detected in any of the tissues studied. Phosphate-independent glutaminase activity was always less than 10% of phosphate-dependent glutaminase activity and therefore must have a minor role in the metabolism of glutamine in lambs.

A consideration of the relative activities of the enzymes at different stages of development indicated that the ileum, spleen, liver, kidney cortex and brain have a substantial potential for glutamine utilization during foetal life. As a lamb matures after birth, there are changes in the metabolism of glutamate and glutamine which indicate that there is a greater potential for net glutamine synthesis in older lambs. This could be associated with the need for detoxification of ammonia in ruminating lambs.

Type
Research Article
Copyright
Copyright © Cambridge University Press 1983

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

Battaglia, F. C. & Meschia, G. (1981). Foetal and placental metabolisms: their interrelationships and impact upon maternal metabolism. Proceedings of the Nutrition Society 40, 99113.CrossRefGoogle ScholarPubMed
Benjamin, A. M. (1981). Control of glutaminase activity in rat brain cortex in vitro: influence of glutamate, phosphate, ammonium, calcium and hydrogen ions. Brain Research 208, 363377.CrossRefGoogle ScholarPubMed
Bergman, E. N. & Heitmann, R. N. (1978). Metabolism of amino acids by the gut, liver, kidneys and peripheral tissues. Federation of American Societies for Experimental Biology 37, 12281232.Google ScholarPubMed
Bergman, E. N., Kaufman, C. F., Wolff, J. E. & Williams, H. H. (1974). Renal metabolism of amino acids and ammonia in fed and fasted pregnant sheep. American Journal of Physiology 226, 833837.CrossRefGoogle ScholarPubMed
Cooper, A. J. L. & Meister, A. (1972). Isolation and properties of highly purified glutamine transaminase. Biochemistry 11, 661671.CrossRefGoogle ScholarPubMed
Cooper, A. J. L. & Meister, A. (1974). Isolation and properties of a new glutamine transaminase from rat kidney. Journal of Biological Chemistry 249, 25542561.CrossRefGoogle ScholarPubMed
Curthoys, N. P. & Kuhlenschmidt, T. (1975). Phosphate-independent glutaminase from rat kidney. Journal of Biological Chemistry 250, 20992105.CrossRefGoogle ScholarPubMed
Curthoys, N. P. & Lowry, O. H. (1973). The distribution of glutaminase isoenzymes in the various structures of the nephron in normal, acidotic and alkalotio rat kidney. Journal of Biological Chemistry 248, 162168.CrossRefGoogle ScholarPubMed
Edwards, E. M., Dhand, U. K., Jeacock, M. K. & Shepherd, D. A. L. (1976). Pyruvate and oxaloacetate metabolism in the kidney cortex of developing sheep. Biology of the Neonate 30, 4954.CrossRefGoogle Scholar
Fiala, S., Fiala, A. E., Keller, R. W. & Fiala, E. S. (1977). γ-glutamyl transpeptidase in colon cancer induced by 1,2-dimethylhydrazine. Archiv für Geschwulstforschung 47, 117122.Google ScholarPubMed
Grandgeorge, M. & Morelis, P. (1976). Partial purification and study of γ-glutamyl transpeptidase of sheep brain cortex capillaries. Biochemie 58, 275284.CrossRefGoogle Scholar
Heitmann, R. N. & Bergman, E. N. (1978). Glutamine metabolism, interorgan transport and glucogenicity in the sheep. American Journal of Physiology 234, E197203.Google ScholarPubMed
Khayam-Bashi, H. (1979). Protein fractionation, nucleic acids and enzymatic activity of cytoplasmic extracts from the intestinal mucosa of sheep. Biochemical Medicine 21, 4046.CrossRefGoogle ScholarPubMed
Kleinman, L. I. (1970). Physiology of the perinatal kidney. In Physiology of the Perinatal Period, vol. 2 (ed. Stave, U.), pp. 679702. New York: Appleton Century Crofts.Google Scholar
Krebs, H. A. (1980). Glutamine metabolism in the animal body. In Glutamine: Metabolism, Enzymology, and Regulation (ed. Mora, J. and Palacioe, R.), pp. 319329. London: Academic Press.CrossRefGoogle Scholar
Lacey, J. H., Bradford, N. M., Joseph, S. K. & McGivan, J. D. (1981). Increased activity of phosphate-dependent glutaminase in liver mitochondria as a result of glucagon treatment of rats. Biochemical Journal 194, 2933.CrossRefGoogle ScholarPubMed
Lewis, D. & Buttery, P. J. (1973). Ammonia toxicity in ruminants. In Proditction Disease in Farm Animals (ed. Payne, J. M., Hibbitt, K. G. and Sansom, B. F.), pp. 201211. London: Baillière Tyndall.Google Scholar
Lowry, O. H., Rosenbrough, N. J., Farr, A. L. & Randall, R. J. (1951). Protein estimation with the folin phenol reagent. Journal of Biological Chemistry 193, 265275.CrossRefGoogle Scholar
Lund, P. (1970). A radiochemical assay for glutamine synthetase, and activity of the enzyme in rat tissues. Biochemical Journal 118, 3539.CrossRefGoogle ScholarPubMed
Lund, P. (1980). Glutamine metabolism in the rat. Federation of European Biochemical Societies Letters 117, K86K92.CrossRefGoogle ScholarPubMed
Lund, P. & Watford, M. (1976). Glutamine as a precursor of urea. In The Urea Cycle (ed. Grisolia, S., Baguena, R. and Mayor, F.), pp. 479488. New York: John Wiley.Google Scholar
McIntyre, T. M. & Curthoys, N. P. (1980). The interorgan metabolism of glutathione. International Journal of Biochemistry 12, 545551.CrossRefGoogle ScholarPubMed
Miller, S. P., Awasthi, Y. C. & Srivastava, S. K. (1976). Studies on human kidney γ-glutamyl transpeptidase. Purification and structural, kinetic and immunological properties. Journal of Biological Chemistry 251, 22712278.CrossRefGoogle ScholarPubMed
Newsholme, E. A. (1980). Reflections on the mechanism of action of hormones. Federation of European Biochemical Societies Letters 117, K121K134.CrossRefGoogle ScholarPubMed
Newsholme, E. A. & Start, C. (1973). Introduction to metabolic pathways. Chapter I of Regulation in Metabolism, pp. 132. London: John Wiley.Google Scholar
Orlowski, M. & Meister, A. (1970). The γ-glutamyl cycle: possible transport system for amino acids. Proceedings of the National Academy of Sciences of the United States of America 67, 12481255.CrossRefGoogle ScholarPubMed
Pell, J. M., Jeacock, M. K. & Shepherd, D. A. L. (1979). Interconversion of glutamate and glutamine in the placenta during development of foetal lambs. Proceedings of the Nutrition Society 38, 19A.Google ScholarPubMed
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.CrossRefGoogle ScholarPubMed
Schmidt, E. (1974). Glutamate dehydrogenase. UV-assay. In Methods of Enzymatic Analysis (ed. Bergmeyer, H. U.), pp. 650656. London and New York: Academic Press.CrossRefGoogle Scholar
Shank, R. P. & Aprison, M. H. (1981). Present status and significance of the glutamine cycle in neural tissue. Life Sciences 28, 837842.CrossRefGoogle Scholar
Szasz, G. (1974). γ-glutamyl transpeptidase. In Methods of Enzymatic Analysis (ed. Bergmeyer, H. U.), pp. 715720. London and New York: Academic Press.CrossRefGoogle Scholar
Tapia, R. (1980). Glutamine metabolism in brain. In Glutamine: Metabolism, Enzymology, and Regulation, (ed. Mora, J. and Palacios, R.), pp. 285297. London: Academic Press.CrossRefGoogle Scholar
Tate, S. S. & Meister, A. (1975). Identity of maleate-stimulated glutaminase with γ-glutamyl transpeptidase in the rat kidney. Journal of Biological Chemistry 250, 46194627.CrossRefGoogle ScholarPubMed
Tsuji, M., Matsuoka, Y. & Nakajima, T. (1977). Studies on formation of γ-glutamyl amines in rat brain and their synthetic and catabolic enzymes. Journal of Neurochemistry 29, 633638.CrossRefGoogle Scholar
Windmueller, H. G. & Spaeth, A. E. (1978). Identification of ketone bodies and glutamine as the major respiratory fuels in vivo for postabsorptive rat intestine. Journal of Biological Chemistry 253, 6976.CrossRefGoogle Scholar
Wolff, J. E. & Bergman, E. N. (1972). Gluconeogenesis from plasma amino acids in fed sheep. American Journal of Physiology 223, 455460.CrossRefGoogle ScholarPubMed
Wolff, J. E., Bergman, E. N. & Williams, H. H. (1972). Net metabolism of plasma amino acids by liver and portal-drained viscera of fed sheep. American Journal of Physiology 223, 438446.CrossRefGoogle ScholarPubMed
Yamamoto, H., Aikawa, T., Matsutaka, H., Okuda, T. & Ishikawa, E. (1974). Interorganal relationships of amino acid metabolism in fed rats. American Journal of Physiology 226, 14281433.CrossRefGoogle ScholarPubMed