Hostname: page-component-745bb68f8f-cphqk Total loading time: 0 Render date: 2025-01-22T08:53:32.006Z Has data issue: false hasContentIssue false
  • English
  • Français

Endogenous nitrogen metabolism and plasma free amino acids in young adults given a ‘protein-free’ diet*

Published online by Cambridge University Press:  09 March 2007

V. R. Young  and
N. S. Scrimshaw
V. R. Young
Affiliation:
Department of Nutrition and Food Science, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
N. S. Scrimshaw
Affiliation:
Department of Nutrition and Food Science, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
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. Variation in endogenous nitrogen metabolism was determined by giving eleven healthy men, aged 17–22, a diet supplying daily only 6 mg N/kg body-weight. Eight subjects were given the diet for 7–10 days and three other subjects were given it for 16 days.

2. Body cell mass (BCM) was calculated from whole-body 40K in ten subjects and basal metabolism was determined in seven subjects during the ‘protein-free’ period. Urine was analysed daily for N and creatinine, and faecal N was measured in pooled samples. Plasma free amino acids, serum albumin and protein were measured in preprandial morning blood samples at the beginning and end of the study.

3. BCM did not change during the ‘protein-free’ period and accounted for 48% of the total body-weight. Basal calorie expenditure amounted to 48 ± 5 kcal/kg BCM per day.

4. Mean daily endogenous urinary N excretion in the eight subjects given the ‘protein-free’ diet for 7–10 days was 36·6 ± 3·0 mg N/kg body-weight, 79·4 ± 4·4 mg N/kg BCM and 1·6 ± 0·2 mg N/basal kcal. Endogenous faecal N excretion was 9·9 ± 1·1 mg N/kg body-weight and accounted for 20% of the total endogenous loss. Results obtained with three other subjects given the diet for 16 days were similar.

5. Plasma essential amino acids were reduced, glutamic acid, alanine and glycine increased, and the ratio of essential to non-essential amino acids decreased after 7 or 10 days of ‘protein-free’ diet.

6. The loss of endogenous N per basal kcal and of faecal N per kg body-weight was lower than the values assumed in the factorial approach to protein requirements by the FAO/WHO (1965) Expert Group on Protein Requirements.

Type
Research Article
Information
British Journal of Nutrition , Volume 22 , Issue 1 , February 1968 , pp. 9 - 20
Copyright
Copyright © The Nutrition Society 1968

References

Allison, J. B. & Wannemacher, R. W. Jr (1965). Am. J. clin. Nutr. 16, 445.CrossRefGoogle Scholar
Annino, J. S. (1964). Clinical Chemistry, 3rd ed. Boston: Little, Brown and Co.Google Scholar
Arroyave, G., Wilson, D., de Funes, C. & Béhar, M. (1962). Am. J. clin. Nutr. 11, 517.CrossRefGoogle Scholar
Ashworth, U. S. (1935). Res. Bull. Mo. agric. Exp. Stn no. 233, p. 20.Google Scholar
Ashworth, U. S. & Cowgill, G. R. (1938). J. Nutr. 15, 73.CrossRefGoogle Scholar
Bricker, M. L. & Smith, J. M. (1951). J. Nutr. 44, 553.CrossRefGoogle Scholar
Clark, H. E., Kenney, M. A., Goodwin, A. F., Goyal, K. & Mertz, E. F. (1963). J. Nutr. 81, 233.CrossRefGoogle Scholar
Clark, H. E., Myers, P., Goyal, K. & Rinehart, J. (1966). Am. J. clin. Nutr. 18, 91.CrossRefGoogle Scholar
Consolazio, C. F., Le Matoush, R. O., Nelson, R. A., Isaac, G. J. & Canham, J. E. (1966). Am. J. clin. Nutr. 18, 443.CrossRefGoogle Scholar
Deuel, H. J. Jr, Sandiford, I., Sandiford, K. & Boothby, W. M. (1928). J. biol. Chem. 76, 391.CrossRefGoogle Scholar
Evans, R. D. (1964). Annual Progress Report, M.I.T.-952-1 Contract AT 30-D-952, U.S. Atomic Energy Commission, Division of Biology and Medicine, 05 1964.Google Scholar
FAO/WHO (1965). Tech. Rep. Ser. Wld Hlth Org. no. 301.Google Scholar
Fomon, S. J., DeMaeyer, E. M. & Owen, G. M. (1965). J. Nutr. 85, 235.CrossRefGoogle Scholar
Gopalan, C. & Narasinga Rao, B. S. (1966). J. Nutr. 90, 213.CrossRefGoogle Scholar
Grande, F. (1961). In Techniques for Measuring Body Composition, p. 172. [Brozek, T., and Herschel, A., editors.] Washington, D.C.: National Academy of Sciences and National Research Council.Google Scholar
Grande, F., Anderson, J. T. & Keys, A. (1958). J. appl. Physiol. 12, 230.CrossRefGoogle Scholar
Harper, A. E. (1964). In Mammalian Protein Metabolism. Vol. 2, p. 87. [Munro, H. N. and Allison, J. B., editors.] New York: Academic Press Inc.CrossRefGoogle Scholar
Hawley, E. E., Murlin, J. R., Nasset, E. S. & Szymanski, T. A. (1948). J. Nutr. 36, 153.CrossRefGoogle Scholar
Holt, L. E. & Snyderman, S. E. (1965). Nutr. Abstr. Rev. 35, 1.Google Scholar
Huang, P. C., Young, V. R., Cholakos, B. & Scrimshaw, N. S. (1966). J. Nutr. 90, 416.CrossRefGoogle Scholar
Kies, C. V., Shortridge, L. & Reynolds, M. S. (1965). J. Nutr. 85, 260.CrossRefGoogle Scholar
Leverton, R. M., Ellison, J., Johnson, N., Pazur, J., Schmidt, F. & Geschwender, D. (1956). J. Nutr. 58, 355.CrossRefGoogle Scholar
McLaren, D. S., Kamel, W. W. & Ayyoub, N. (1965). Am. J. clin. Nutr. 17, 152.CrossRefGoogle Scholar
Martin, C. J. & Robison, R. (1922). Biochem. J. 16, 407.CrossRefGoogle Scholar
Miller, D. S. & Bender, A. E. (1955). Br. J. Nutr. 9, 382.CrossRefGoogle Scholar
Mitchell, H. H. & Hamilton, T. S. (1949). J. biol. Chem. 178, 345.CrossRefGoogle Scholar
Moore, F. D., Olsen, K. O., McMurrey, J. D., Parker, H. V., Ball, M. R. & Boyden, C. M. (1963). The Body Cell Mass and Its Supporting Environment. Philadelphia: Saunders.Google Scholar
Mueller, A. J. & Cox, W. M. Jr (1947). J. Nutr. 34, 285.CrossRefGoogle Scholar
Munro, H. N. (1964). In Mammalian Protein Metabolism. Vol. 1, p. 381. [Munro, H. N. and Allison, J. B., editors.] New York: Academic Press Inc.CrossRefGoogle Scholar
Murlin, J. R., Edwards, L. E., Hawley, E. E. & Clark, L. C. (1946 a). J. Nutr. 31, 533.CrossRefGoogle Scholar
Murlin, J. R., Edwards, L. E., Hawley, E. E. & Clark, L. C. (1946 b). J. Nutr. 31, 555.CrossRefGoogle Scholar
Rose, W. C. (1957). Nutr. Abstr. Rev. 27, 631.Google Scholar
Scrimshaw, N. S. (1962–1963). Harvey Lect. 58, 181.Google Scholar
Scrimshaw, N. S., Bressani, R., Béhar, M. & Viteri, F. (1958). J. Nutr. 66, 485.CrossRefGoogle Scholar
Scrimshaw, N. S., Young, V. R., Schwartz, R., Piché, M. L. & Das, J. B. (1966). J. Nutr. 89, 9.CrossRefGoogle Scholar
Smith, M. (1926). J. biol. Chem. 68, 15.CrossRefGoogle Scholar
Smuts, D. B. (1935). J. Nutr. 9, 403.CrossRefGoogle Scholar
Swendseid, M. E. & Dunn, M. S. (1956). J. Nutr. 58, 507.CrossRefGoogle Scholar
Swendseid, M. E., Tuttle, S. G., Figueroa, W. S., Mulcare, D., Clark, A. J. & Massey, F. J. (1966). J. Nutr. 88, 239.CrossRefGoogle Scholar
Tuttle, S. G., Swendseid, M. E., Mulcare, D., Griffith, W. H. & Bassett, S. H. (1959). Metabolism 8, 61.Google Scholar
Venkat Rao, S., Daniel, V. A., Joseph, A., ASankaran, A. N. & Swaminathan, M. (1964). J. Nutr. Dietet. 1, 103.Google Scholar
Watt, B. K. & Merril, A. L. (1963). Composition of Foods. Agric. Handbook no. 8. Washington, D.C.: United States Drug Administration.Google Scholar
Whitehead, R. G. & Dean, R. F. A. (1964). Am. J. clin. Nutr. 14, 320.CrossRefGoogle Scholar