Hostname: page-component-7bb8b95d7b-495rp Total loading time: 0 Render date: 2024-09-12T11:50:48.568Z Has data issue: false hasContentIssue false

Protein metabolism in skeletal muscle: the effect of feeding and fasting on muscle RNA, free amino acids and plasma insulin concentrations

Published online by Cambridge University Press:  09 March 2007

D. J. Millward
Affiliation:
Clinical Nutrition and Metabolism Unit, Hospital for Tropical Diseases, St Pancras Way, London NW1 2PE
D. O. Nnanyelugo
Affiliation:
Clinical Nutrition and Metabolism Unit, Hospital for Tropical Diseases, St Pancras Way, London NW1 2PE
W. P. T. James
Affiliation:
Clinical Nutrition and Metabolism Unit, Hospital for Tropical Diseases, St Pancras Way, London NW1 2PE
P. J. Garlick
Affiliation:
Clinical Nutrition and Metabolism Unit, Hospital for Tropical Diseases, St Pancras Way, London NW1 2PE
Rights & Permissions [Opens in a new window]

Abstract

Core share and HTML view are not available for this content. However, as you have access to this content, a full PDF is available via the ‘Save PDF’ action button.

1. This study set out to measure the sensitivity of muscle RNA content to food intake and food restriction, and to relate this to plasma insulin and intracellular amino acid concentrations.

2. Young rats were trained for 2 weeks to consume their daily food ration in a single 4 h period. After this time they had resumed normal growth. The rats were killed at intervals over 24 h and subsequently at daily intervals. One group was given a protein-free meal in place of the stock diet and a similar procedure was followed. Measurements were made of plasma insulin, concentration of nucleic acids and protein in liver, heart and skeletal muscle, and free amino acids in the gastrocnemius muscle.

3. Following the meal there was a fivefold increase in plasma insulin, which was accompanied by small increases in the concentrations of the intracellular amino acids in muscle. In all the tissues, after feeding, the RNA:DNA ratio increased by (%) 20, 19 and 12 in liver, skeletal and heart muscle respectively.

4. During the fasting period the plasma insulin decreased, and this decrease was accompanied by rapid losses of RNA from liver, muscle and heart at similar rates. There were increases in the concentrations of the essential amino acids, especially methionine and the branched-chain amino acids, but decreases, in general, in those of the non-essential amino acids. When the protein-free meal was given, there was a small increase in the plasma insulin, but the RNA was lost from the three tissues at the same rate as in the starved rats. There was, however, a transient fall in the concentrations of the essential amino acids.

5. The rapid changes in muscle RNA concentrations following food intake demonstrate that the minimum turnover rate of RNA in this tissue must be considerably faster than has been previously reported, and must be similar to that in liver. There is a direct correlation between tissue RNA concentration and that of plasma insulin, but little correlation between tissue RNA concentration and that of the intracellular essential amino acids.

Type
General Nutrition
Copyright
Copyright © The Nutrition Society 1974

References

REFERENCES

Adibi, S. A. (1971). Am. J. Physiol. 221, 829.CrossRefGoogle Scholar
Benson, J. V., Gordon, M. J. & Patterson, J. A. (1967). Analyt. Biochem. 18, 228.CrossRefGoogle Scholar
Blobel, G. & Potter, V. R. (1968). Biochim. biophys. Acta 166, 48.CrossRefGoogle Scholar
Bloxam, D. L. (1972). Br. J. Nutr. 27, 233.CrossRefGoogle Scholar
Brunschede, H. & Bremer, H. (1971). J. mol. Biol. 57, 35.CrossRefGoogle Scholar
Cahill, G. F. Jr (1971). Diabetes 20, 785.CrossRefGoogle Scholar
Clemens, M. J. & Korner, A. (1971). Nature New Biol. 232, 252.CrossRefGoogle Scholar
Enwonwu, C. O. & Munro, H. N. (1970). Archs Biochem. Biophys. 138, 523.CrossRefGoogle Scholar
Enwonwu, C. O., Stambaugh, R. & Sreebny, L. (1971). J. Nutr. 101, 337.CrossRefGoogle Scholar
Felig, P., Pozefsky, T., Marliss, E. & Cahill, G. F. Jr (1970). Science, N.Y. 167, 1003.CrossRefGoogle Scholar
Garlick, P. J., Millward, D. J. & James, W. P. T. (1973). Biochem. J. 136, 935.CrossRefGoogle Scholar
Gerber, G., Gerber, G. & Altman, K. I. (1960). J. biol. Chem. 235, 2682.CrossRefGoogle Scholar
Giles, K. W. & Meyers, A. (1965). Nature, Lond. 206, 93.CrossRefGoogle Scholar
Guidotti, G. G. (1972). Proc. Nutr. Soc. 31, 179.CrossRefGoogle Scholar
Hales, C. N. & Randle, P. J. (1963). Biochem. J. 88, 137.CrossRefGoogle Scholar
Henderson, A. R. (1972). Proc. Nutr. Soc. 31, 291.CrossRefGoogle Scholar
Hirsch, C. A. & Hiatt, H. H. (1966). J. biol. Chem. 241, 5936.CrossRefGoogle Scholar
Ichihara, A. & Koyama, E. (1966). J. Biochem., Tokyo 59, 160.CrossRefGoogle Scholar
Jefferson, L. S., Koehler, J. O. & Morgan, H. E. (1972). Proc. natn. Acad. Sci. U.S.A. 69, 816.CrossRefGoogle Scholar
Krebs, H. A. (1972). In Advances in Enzyme Regulation Vol. 10, p. 397 [Weber, G., editor]. Oxford: Pergamon Press.Google Scholar
Lowry, O. H., Rosebrough, N. J., Farr, A. L. & Randall, R. J. (1951). J. biol. Chem. 193, 265.CrossRefGoogle Scholar
Manchester, K. L. (1967). Biochem. J. 105, 13C.CrossRefGoogle Scholar
Manchester, K. L. (1970 a). Biochem. J. 117, 457.CrossRefGoogle Scholar
Manchester, K. L. (1970 b). In Mammalian Protein Metabolism Vol. 4, Ch. 33 [Munro, H. N., editor’. New York and London: Academic Press.Google Scholar
Marliss, E. B., Aoki, T. T., Pozefsky, T., Most, A. S. & Cahill, G. F. (1971). J. clin. Invest. 50, 814.CrossRefGoogle Scholar
Millward, D. J. (1970 a). Clin. Sci. 39, 577.CrossRefGoogle Scholar
MiIlward, D. J. (1970 b). Clin. Sci. 39, 591.CrossRefGoogle Scholar
Millward, D. J. & Garlick, P. J. (1972). Proc. Nutr. Soc. 31, 257.CrossRefGoogle Scholar
Millward, D. J., Garlick, P. J., James, W. P. T., Nnanyelugo, D. O. & Ryatt, J. S. (1973). Nature, Lond. 241, 204.CrossRefGoogle Scholar
Morgan, H. E., Jefferson, L. S., Wolpert, E. B. & Rannels, D. E. (1971). J. biol. Chem. 246, 2163.CrossRefGoogle Scholar
Munro, H. N. (1968). Fedn Proc. Fedn Am. Socs exp. Biol. 27, 1231.Google Scholar
Munro, H. N. & Fleck, A. (1969). In Mammalian Protein Metabolism Vol. 3, p. 423 [Munro, H. N., editor] New York and London: Academic Press.CrossRefGoogle Scholar
Oxender, D. L. & Christensen, H. N. (1963). J. biol. Chem. 238, 3686.CrossRefGoogle Scholar
Payne, P. R. & Stewart, R. J. C. (1972). Lab. Anim. 6, 135.CrossRefGoogle Scholar
Potter, V. R., Baril, E. F., Watanabe, M. & Whittle, E. D. (1968). Fedn Proc. Fedn Am. Socs exp. Biol. 27, 1238.Google Scholar
Rebolledo, O. R. & Gagliardino, J. J. (1971). J. Interdiscip. Cycle Res. 2, 101.CrossRefGoogle Scholar
Steiner, D. F. & King, J. (1966). Biochim. biophys. Acta 119, 510.CrossRefGoogle Scholar
Watanabe, M., Potter, V. R. & Pitot, H. C. (1968). J. Nutr. 95, 207.CrossRefGoogle Scholar
Waterlow, J. C. & Stephen, J. M. L. (1968). Clin. Sci. 35, 287.Google Scholar
Weber, G. (1972). Israel. J. med. Sci. 8, 325.Google Scholar
Wool, I. G. (1963). Biochim. biophys. Acta 68, 28.CrossRefGoogle Scholar
Wool, I. G. (1972). Proc. Nutr. Soc. 31, 185.CrossRefGoogle Scholar
Young, V. R. (1970). In Mammalian Protein Metabolism Vol. 4, Ch. 40 [Munro, H. N., editor’. New York and London: Academic Press.Google Scholar