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Effects of prolonged treatment of lactating goats with bovine somatotropin on aspects of adipose tissue and liver metabolism

Published online by Cambridge University Press:  01 June 2009

Richard G. Vernon
Affiliation:
Hannah Research Institute, Ayr KA6 5HL, UK
Anne Faulkner
Affiliation:
Hannah Research Institute, Ayr KA6 5HL, UK
Eric Finley
Affiliation:
Hannah Research Institute, Ayr KA6 5HL, UK
Paul W. Watt
Affiliation:
Hannah Research Institute, Ayr KA6 5HL, UK
Victor A. Zammit
Affiliation:
Hannah Research Institute, Ayr KA6 5HL, UK

Summary

The effects of prolonged (22 weeks) treatment of lactating goats with bovine somatotropin on the metabolism of adipose tissue and liver has been investigated. Somatotropin treatment resulted in smaller adipocytes, decreased rate of fatty acid synthesis and decreased total acetyl-CoA carboxylase activity of adipocytes, but with no change in the proportion of this enzyme in the active state. The rate of acylglycerol glycerol synthesis from glucose of adipocytes tended to decrease as did total glucose utilization by the tissue. Glucose conversion to lactate was unchanged by somatotropin treatment but glucose conversion to other products was decreased. Maximum response of adipose tissue to insulin was unchanged but the sensitivity to insulin decreased on somatotropin treatment. Treatment with somatotropin had no effect on basal lipolysis and decreased maximum response to the β-agonist isoproterenol, but this probably reflects the rate of isoproterenol-stimulated lipolysis varying with cell volume in adipocytes. No apparent change in response either to α2-adrenergic agonists or to adenosine was apparent. The number of β-adrenergic receptors was unchanged in adipocyte membranes but the number of α2-adrenergic receptors increased. The rate of hepatic gluconeogenesis in vitro, the activity of key gluconeogenic enzymes and the modulation of the rate of gluconeogenesis by butyrate were unchanged except for the effect of this latter agent on gluconeogenesis from propionate. Hepatic ketogenic activity, as indicated by the activity of carnitine palmitoyl-CoA-transferase-1 and the concentrations of carnitine and acyl carnitines, was unchanged by treatment. Thus at the end of a prolonged period of treatment with somatotropin in lactating goats, lipid synthesis in adipose tissue is still decreased but no effects on liver lipid and carbohydrate metabolism were apparent.

Type
Original Articles
Copyright
Copyright © Proprietors of Journal of Dairy Research 1995

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References

REFERENCES

Ballard, F. J., Hanson, R. W., Kronfeld, D. S. & Raggi, F. 1968 Metabolic changes in liver associated with spontaneous ketosis and starvation in cows. Journal of Nutrition 95 160172CrossRefGoogle Scholar
Bauman, D. E., Peel, C. J., Steinhour, W. D., Reynolds, P. J., Tyrrell, H. F., Brown, A. C. G. & Haaland, G. L. 1988 Effect of bovine somatotropin on metabolism of lactating dairy cows: influence on rates of irreversible loss and oxidation of glucose and nonesterified fatty acids. Journal of Nutrition 118 10311040CrossRefGoogle ScholarPubMed
Bauman, D. E. & Vernon, R. G. 1993 Effects of exogenous bovine somatotropin on lactation. Annual Review of Nutrition 13 437461CrossRefGoogle ScholarPubMed
Bergmeyer, H. U., Bernt, E., Schmidt, F. & Stork, H. 1974 D-glucose. Determination with hexokinase and glucose 6-phosphate dehydrogenase. In Methods of Enzymatic Analysis, 2nd English edn, vol. 3, pp. 11961201 (Ed. Bergmeyer, H. U.). New York: Academic PressGoogle Scholar
Bradford, M. M 1976 A rapid and sensitive method for the quantitation of microgram quantities of protein utilizing the principle of protein dye-binding. Analytical Biochemistry 72 248254CrossRefGoogle ScholarPubMed
Chilliard, Y., Durand, G., Sauvant, D. & Morand-Fehr, P. 1978 [Metabolic activity of adipose tissue in the goat during pregnancy and at the start of lactation.] Comptes Rendus Hebdomadaires des Séances de I'Académie des Sciences D 287 11311134Google Scholar
Cohick, W. S., Slepetis, R., Harkins, M. & Bauman, D. E. 1989 Effects of exogenous bovine somatotropin (bST) on net flux rates of glucose and insulin across splanchnic tissues of lactating cows. FASEB Journal 3 A938Google Scholar
Filsell, O. H., Jakrett, I. G., Taylor, P. H. & Keech, D. B. 1969 Effects of fasting, diabetes and glucocorticoids on gluconeogenic enzymes in the sheep. Biochimica et Biophysica Acta 184 5463CrossRefGoogle ScholarPubMed
Halenz, D. R., Feng, J.-Y., Hegre, C. S. & Lane, M. D. 1962 Some enzymic properties of mitochondrial propionyl carboxylase. Journal of Biological Chemistry 237 21402147CrossRefGoogle ScholarPubMed
Knapp, J. R., Freetly, H. C., Reis, B. L., Calvert, C. C. & Baldwin, R. L. 1992 Effects of somatotropin and substrates on patterns of liver metabolism in lactating dairy cattle. Journal of Dairy Science 75 10251035CrossRefGoogle ScholarPubMed
Knight, C. H., Fowler, P. A. & Wilde, C. J. 1990 Galactopoietic and mammogenic effects of long-term treatment with bovine growth hormone and thrice daily milking in goats. Journal of Endocrinology 127 129138CrossRefGoogle ScholarPubMed
Lanna, D. P. D., Houseknecht, K. L., Harris, D. M. & Bauman, D. E. 1992 Effect of bovine somatotropin (bST) on lipolysis, lipogenesis and activities of some enzymes in adipose tissue of lactating cows. Journal of Animal Science 70 (Suppl. 1) 193AGoogle Scholar
Lowry, O. H., Rosebrough, N. J., Farr, A. L. & Randall, R. J. 1951 Protein measurement with the Folin phenol reagent. Journal of Biological Chemistry 193 265275CrossRefGoogle ScholarPubMed
McNamara, J. P. & Hillers, J. K. 1986 Adaptations in lipid metabolism of bovine adipose tissue in lactogenesis and lactation. Journal of Lipid Research 27 150157CrossRefGoogle ScholarPubMed
Pocius, P. A. & Herbein, J. H. 1986 Effects of in vivo administration of growth hormone on milk production and in vitro hepatic metabolism in dairy cattle. Journal of Dairy Science 69 713720CrossRefGoogle ScholarPubMed
Robertson, J. P., Faulkner, A. & Vernon, R. G. 1982 Regulation of glycolysis and fatty acid synthesis from glucose in sheep adipose tissue. Biochemical Journal 206 577586CrossRefGoogle ScholarPubMed
Robinson, I. N. & Zammit, V. A. 1982 Sensitivity of carnitine acyltransferase I to malonyl-CoA inhibition in isolated rat liver mitochondria is quantitatively related to hepatic malonyl-CoA concentration in vivo. Biochemical Journal 206 177179CrossRefGoogle ScholarPubMed
Sechen, S. J., Dunshea, F. R. & Bauman, D. E. 1990 Somatotropin in lactating cows: effect on response to epinephrine and insulin. American Journal of Physiology 258 E582E588Google Scholar
Vernon, R. G. 1976 Effect of dietary fats on ovine adipose tissue metabolism. Lipids 11 662669CrossRefGoogle ScholarPubMed
Vernon, R. G. 1989 Influence of somatotropin on metabolism. In Use of Somatotropin in Livestock Production, pp. 3150 (Eds Sejrsen, K., Vestergaard, M. and Neimann-Sorensen, A.). London: Elsevier Applied ScienceGoogle Scholar
Vernon, R. G., Clegg, R. A. & Flint, D. J. 1981 Metabolism of sheep adipose tissue during pregnancy and lactation. Biochemical Journal 200 307314CrossRefGoogle ScholarPubMed
Vernon, R. G., Faulkner, A., Finley, E., Pollock, H. & Taylor, E. 1987 Enzymes of glucose and fatty acid metabolism of liver, kidney, skeletal muscle, adipose tissue and mammary gland of lactating and non-lactating sheep. Journal of Animal Science 64 13951411CrossRefGoogle ScholarPubMed
Vernon, R. G. & Finley, E. 1985 Regulation of lipolysis during pregnancy and lactation in sheep: response to noradrenaline and adenosine. Biochemical Journal 230 651656CrossRefGoogle ScholarPubMed
Vernon, R. G. & Finley, E. 1988 Roles of insulin and growth hormone in the adaptations of fatty acid synthesis in white adipose tissue during the lactation cycle in sheep. Biochemical Journal 256 873878CrossRefGoogle ScholarPubMed
Vernon, R. G. & Taylor, E. 1988 Insulin, dexamethasone and their interactions in the control of glucose metabolism in adipose tissue from lactating and non-lactating sheep. Biochemical Journal 256 509514CrossRefGoogle Scholar
Watt, P. W., Finley, E., Cork, S., Clegg, R. A. & Vernon, R. G. 1991 Chronic control of the β-and α2- adrenergic systems of sheep adipose tissue by growth hormone and insulin. Biochemical Journal 273 3942CrossRefGoogle Scholar