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Energy balance in rats given chronic hormone treatment

1. Effects of long-acting insulin

Published online by Cambridge University Press:  09 March 2007

Christopher J. H. Woodward
Affiliation:
Nutrition Division, Department of Food and Nutritional Sciences, King's College (KQC), Campden Hill Road, London W8 7AH
Peter W. Emery
Affiliation:
Nutrition Division, Department of Food and Nutritional Sciences, King's College (KQC), Campden Hill Road, London W8 7AH
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Abstract

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1. Sprague–Dawley rats were injected for 16 d with long-acting insulin, and energy balance was calculated using the comparative carcass technique. Two experiments were carried out with females (starting weights 150 and 90 g respectively), and one with males (starting weight 150 g). In a fourth experiment, cytochrome c oxidasc (EC 1.9.3.1) activity was measured as an indicator of the capacity for substrate oxidation.

2. Insulin increased weight gain by up to 57% (P < 0.01 for all studies). Metabolizable energy intake (kJ/d) was also consistently higher in the treated groups, by up to 34% (P < 0.01 for all studies). The excess weight gained by the insulin-treated rats was predominantly due to fat deposition.

3. Energy expenditure, calculated as the difference between metabolizable intake and carcass energy gain. was expressed on a whole-body basis, or relative to either metabolic body size (kg body-weight0.75) or fat-free mass. Insulin consistently raised energy expenditure, regardless of the method of expression, but this change reached statistical significance in only two of the nine comparisons.

4. Cytochrome c oxidase activity was not affected by insulin treatment in either interscapular brown adipose tissue or gastrocnemius muscle. In liver, total enzyme activity (U/tissue) was increased from 2928 (se 162) in the controls to 3940 (se 294) in the treated group (P < 0.02), but specific activity (U/mg protein) was unchanged.

5. It is concluded that, despite causing substantial hyperphagia, insulin treatment only slightly increases energy expenditure in rats. The costs of increased tissue deposition may account for this change.

Type
Energy Metabolism
Copyright
Copyright © The Nutrition Society 1989

References

Amirthanayagam, V. (1985) Effects of chronic insulin treatment on energy balance in young male rats. MSc Thesis, University of London.Google Scholar
Balon, T. W., Zorzano, A., Goodman, M. N. & Ruderman, N. B. (1984) Insulin increases thermogenesis in rat skeletal muscle following exercise. American Journal of Physiology 248, E148E151.Google Scholar
Bartness, T. J., Billington., C. J., Levine, A. S., Morley, J. E., Brown, D. M. & Rowland, N. E. (1986) Insulin and metabolic efficiency in rats. 1, Effects of sucrose feeding and BAT axotomy. American Journul of Physiology 251, R1109R1117.Google Scholar
Beaton, J. R., Felaki, V. & Stevenson, J. A. F. (1965) Insulin hyperphdgia in rats fed a low-protein diet. Canadian Journal qf Physiology and Pharmacology 43, 225233.CrossRefGoogle ScholarPubMed
Bernardis, L. L., Luboshitzky, R. & Bellinger, L. L. (1981) Long-term effects of insulin in weanling rats with dorsomeidial hypothalamic hypophagia: food intake, efficiency of food utilization, body weight and compostion. Physiology and Beliuviour 27, 469474.Google Scholar
Brandes, J. S. (1977) Insulin-induced overeating in the rat. Physiology and Behaviour 18, 10951102.CrossRefGoogle ScholarPubMed
Christin, L., Nacht, C.-A., Vernet, O., Ravussin, E., Jequier, E. & Acheson, K. J. (1986) Insulin: its role in the thermic effect of glucose. Journal of Clinical Investigation 77, 17471755.CrossRefGoogle ScholarPubMed
Harris, R. B. S., Kasser, T. R. & Martin, R. J. (1986) Dynamics of recovery of body composition after overfeeding, food restriction or starvation of mature female rats. Journal of Nutrition 116, 25362546.CrossRefGoogle ScholarPubMed
Hausberger, F. X. & Hausberger, B. C. (1958) Effect of insulin and cortisone and weight gain, protein and fat content in rats. American Journal of Physiology 193, 455460.CrossRefGoogle Scholar
Hervey, E. & Hervey, G. R. (1981) The influence of sex hormones on energy balance. In The Body Weight Regulatory System: Normal and Disturbed Mechanisms pp. 345352 [Cioffi, L.A., James, W. P. T. and van Itallie, T. B., editors]. New York: Raven Press.Google Scholar
Lotter, E. C. & Woods, S. C. (1977) Injections of insulin and changes of body weight. Physiology and Behaviour 18, 293297.CrossRefGoogle ScholarPubMed
McCracken, K. J. (1986) Nutritional obesity and body composition. Proceedings of the Nutrition Society 45, 91100.CrossRefGoogle ScholarPubMed
Mackay, E. M., Callaway, J. W. & Barnes, R. H. (1940) Hyperalimentation in normal animals produced by protamine insulin. Journal of Nutrition 20, 5966.CrossRefGoogle Scholar
Markwell, M. A. K., Haas, S. M., Bieber, L. L. & Tolbert, N. E. (1978) A modification of the Lowry procedure to simplify protein determination in membrane and lipoprotein samples. Analytical Biochemistry 87, 206210.CrossRefGoogle ScholarPubMed
Miller, D. S. & Mumford, P. (1966) Obesity: physical activity and nutrition. Proceedings of the Nutrition Society 25, 100107.CrossRefGoogle ScholarPubMed
Moley, J. F., Morrison, S. D. & Norton, J. A. (1985) Insulin reversal of cancer cachexia in rats. Cancer Research 45, 49254931.Google ScholarPubMed
Morrison, S. D. (1984) Synergistic stimulation of food intake by simultaneous insulin and cold. Journal of Applied Physiology 57, 2833.CrossRefGoogle ScholarPubMed
Passmore, R. & Eastwood, M. A. (1986) Human Nutrition and Dietetics 8th ed., p. 17. Edinburgh: Churchill Livingstone.Google Scholar
Pullar, J. D. & Webster, A. J. F. (1977) The energy cost of fat and protein deposition in the rat. British Journal of Nutrition 37, 355363.CrossRefGoogle ScholarPubMed
Rothwell, N. J., Stock, M. J. & Warwick, B. P. (1985) Involvement of insulin in the acute thermogenic responses to food and nonmetabolizable substances. Metabolism 34, 4347.CrossRefGoogle ScholarPubMed
Schemmel, R. A., Teague, R. J. & Bray, G. A. (1982) Obesity in Osborne Mendel and S 5B/PL rats: effects of sucrose solutions, castration, and treatment with estradiol or insulin. American Journal uf Physiology 243, R347R353.Google ScholarPubMed
Snedecor, G. W. & Cochran, W. G. (1978) Statistical Methods 6th ed., pp. 114117. Iowa: Iowa State University Press.Google Scholar
Torbay, N., Bracco, E. F., Geliebter, A., Stewart, I. M. & Hashim, S. A. (1985) Insulin increases body fat despite control of food intake and physical activity. American Journal of Physiology 248, R120R124.Google ScholarPubMed
Vasselli, J. R. & Sclafani, A. (1979) Hyperreactivity to aversive diets in rats produced by injection of insulin or tolbutamide, but not by food deprivation. Physiology and Behaviour 23, 557567.CrossRefGoogle Scholar
Webster, A. J. F. (1981) The energetic efficiency of metabolism. Proceedings of the Nutrition Society 40, 121128.CrossRefGoogle ScholarPubMed
Wharton, D. C. & Tzagoloff, A. (1967) Cytochrome oxidase from beef heart mitochondria. In Methods in Enzymology Vol. 10, pp. 245250 [Colowick, S.P. and Kaplan, N. O., editors]. New York and London: Academic Press.Google Scholar
Woodward, C. J. H. & Emery, P. W. (1985) Energy utilization during insulin-induced hyperphagia in rats. Proceedings of the Nutrition Society 44, 79A.Google Scholar