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Relationship between tissue mobilization and storage in the rat *

Published online by Cambridge University Press:  09 March 2007

Christiani Jeyakumar Henry ,
Philip R Payne  and
Amal Ghusain-Choueiri
Christiani Jeyakumar Henry
Affiliation:
School of Biological and Molecular Sciences, Oxford Brookes University, Gipsy Lane, Oxford OX3 OBP
Philip R Payne
Affiliation:
Human Nutrition Unit, London School of Hygiene and Tropical Medicine, Taviton Street, London WClH 0BT
Amal Ghusain-Choueiri
Affiliation:
School of Biological and Molecular Sciences, Oxford Brookes University, Gipsy Lane, Oxford OX3 OBP
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Abstract

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The amount of energy mobilized or stored as protein, expressed as a proportion of the total energy stored or mobilized (defined as the P ratio, Payne & Dugdale, 1977), was investigated in the young male (rapid growth) and adult female (slow growth) rat. Energy mobilization was induced by a 3 d fast and the changes in body content of fat and lean tissues were used to estimate the fasting P ratio (Pfast). Tissue storage was subsequently effected by 17 d of refeeding and the corresponding ratio (Prefed) was calculated from the amounts of lean and fat tissue regained. The same experimental protocol was used for measuring Pfast and Prefed in weanling (30d) and adult (130d) rats. Weight-matched individuals were assigned to three groups. All animals in group 1 were killed at the beginning of the experiment. Animals in group 2 were fasted for 3d and then killed. Group 3 animals were first fasted for 3d, then had free access to a stock diet for a further 17 d before being killed. During fasting, a close linear relationship was found between weight change and body energy changes (r 0·985, and r 0·92, P < 0·001 for weanlings and adult rats respectively) and between carcass N loss and urinary N loss (r 0·933, P < 0·001). These relationships were used to estimate the body energy and N content of each animal at the end of the initial fasting period. Hence, both Pfast and Prefed values could be calculated for all individuals at both ages. When Pfast and Prefed were calculated for adult rats, the mean values were similar (0·138 (SE 0·002) and 0·130 (SE 0·006) respectively). Individually, the Pfast, and Prefed values were correlated (r 0·54, P = 0·058). In weanling rats, the mean Prefed value was about 2·5 times the Pfast (0·421 (SE 0·0113) v. 0·156 (SE 0·004)). Despite the differences in Pfast and Prefed, the individual values were again correlated (r 0·668, P < 0·05). These results support the suggestion made by Payne & Dugdale (1977), that particular P- ratio values are characteristic of individuals and describe the extent to which protein is mobilized or stored during fasting or refeeding. These observations are discussed in relation to the predictions made by the Payne-Dugdale model.

Keywords

Energy-protein mobilizationEnergy-protein storageP ratio
Type
General Nutrition
Information
British Journal of Nutrition , Volume 78 , Issue 1 , July 1997 , pp. 131 - 141
Copyright
Copyright © The Nutrition Society 1997

References

REFERENCES

Bodwell, C. E., Schuster, E. M., Kyle, E., Brooks, B., Womack, M., Steele, P. & Ahrens, R. (1979). Obligatory urinary and faecal nitrogen losses in young women, older men, and young men and the factorial estimation of adult human protein requirements. American Journal of Clinical Nutrition 32, 2450–2459.CrossRefGoogle Scholar
Bradstreet, R. (1965). The Kjeldahl Method for Organic Nitrogen. New York and London: Academic Press.Google Scholar
Donaldson, H. H. (1915). Memoirs of the Wistar Institute of Anatomy and Biology, vol 6. Philadelphia: Wistar Institute.Google Scholar
Dugdale, A. E. & Payne, P. R. (1975). Pattern of fat and lean tissue deposition in children. Nature 256, 725–727.CrossRefGoogle ScholarPubMed
Dulloo, A. G., Henry, C. J. K., Ismail, M. N., Jacquet, J. & Girardier, L. (1994). Predisposition to obesity in humans: an evolutionary advantage turned deleterious. International Journal of Food Sciences and Nutrition 45, 159–168.CrossRefGoogle Scholar
Dulloo, A. G., Jacquet, J. & Girardier, L. (1996). Autoregulation of body composition during weight recovery in humans: the Minnesota Experiment revisited. International Journal of Obesity 20, 393–405.Google ScholarPubMed
Forbes, G. B. (1987). Lean body mass-body fat interrelationships in humans. Nutrition Reviews 45, 225–231.CrossRefGoogle ScholarPubMed
Garrow, J. S. (1974). Energy Balance and Obesity in Man. Amsterdam: North-Holland.Google Scholar
Garrow, J. S. (1978). Energy Balance and Obesity in Man. Amsterdam: North-Holland.Google Scholar
Henry, C. J. K., Rivers, J. P. W. & Payne, P. R. (1988). Protein and energy metabolism in starvation reconsidered. European Journal of Clinical Nutrition 42, 543–549.Google ScholarPubMed
Keys, A., Brozek, J., Henchel, A., Michelsen, O. & Taylor, H. L. (1950). The Biology of Human Starvation. Minnesota: University of Minnesota Press.CrossRefGoogle Scholar
Kleiber, M. (1975). The Fire of Life. New York: Krieger.Google Scholar
Miller, D. S. & Payne, P. R. (1959). A ballistic bomb calorimeter. British Journal of Nutrition 13, 501.CrossRefGoogle ScholarPubMed
Njaa, L. R. (1963). A Study on the Mitchell Method for Determination of the Biological Value of Protein. Bergen: Director of Fisheries.Google Scholar
Payne, P. R. & Dugdale, A. E. (1977). A model for the prediction of energy balance and body weight. Annals of Human Biology 4, 525–535.CrossRefGoogle Scholar
Prentice, A. M., Goldberg, G. R., Jebb, S. A., Black, A. E., Murgatroyd, P. R. & Diaz, E. O. (1991). The physiological response to slimming. Proceedings of the Nutrition Society 50, 441–458.CrossRefGoogle ScholarPubMed
Rothwell, N. J. & Stock, M. J. (1981). Regulation of energy balance. Annual Review of Nutrition 1, 235–256.CrossRefGoogle ScholarPubMed
Swift, R. W. & French, C. E. (1954). Energy Metabolism and Nutrition. Washington: Scarecrow.CrossRefGoogle Scholar