Skip to main content
NCBI home page
Biochemical Journal logoLink to Biochemical Journal
. 1985 Jul 1;229(1):19–29. doi: 10.1042/bj2290019

Amino acid metabolism by perfused rat hindquarter. Effects of insulin, leucine and 2-chloro-4-methylvalerate.

E J Davis, S H Lee
PMCID: PMC1145145  PMID: 3899101

Abstract

Hindquarters from starved rats were perfused without substrates but in the presence of an O2- and CO2-carrying perfluorocarbon emulsion to evaluate principally the metabolism of individual endogenous and protein-derived amino acids by this muscle preparation. This experimental model was shown, by a battery of metabolite measurements, to maintain cellular homoeostasis for at least 2h. The net appearance of most amino acids closely approximated their frequency of occurrence in muscle proteins, showing that they are not significantly metabolized. Exceptions were the branched-chain amino acids, methionine and those amino acids that are interconvertible with intermediates of the citrate cycle and pyruvate through coupled transaminations. The evidence indicates that only valine, isoleucine, aspartate and probably methionine can be catabolized by skeletal muscle to provide carbon precursors for glutamate/glutamine and alanine that are formed de novo by protein-catabolic muscle. The protein-sparing effects of insulin and leucine were confirmed. Although each decreased proteolysis and the net appearance of free amino acids, they were generally without effect on the ratios of amino acids formed. 2-Chloro-4-methylvalerate selectively stimulated the removal rate for the branched-chain amino acids, confirming the idea that the branched-chain oxo acid dehydrogenase normally limits the rate of their oxidation by muscle. It is also concluded that, since alanine was not formed in excess of that found in muscle proteins when no glucose was added as substrate, the excess of alanine (carbon) released from muscles in other studies is derived to a large extent, but not exclusively, from preformed carbohydrate.

Full text

PDF
19

Selected References

These references are in PubMed. This may not be the complete list of references from this article.

  1. BARANY M., GAETJENS E., BARANY K., KARP E. COMPARATIVE STUDIES OF RABBIT CARDIAC AND SKELETAL MYOSINS. Arch Biochem Biophys. 1964 Jul 20;106:280–293. doi: 10.1016/0003-9861(64)90189-4. [DOI] [PubMed] [Google Scholar]
  2. Caldwell M. D., Lacy W. W., Exton J. H. Effects of adrenalectomy on the amino acid and glucose metabolism of perfused rat hindlimbs. J Biol Chem. 1978 Oct 10;253(19):6837–6844. [PubMed] [Google Scholar]
  3. Chang T. W., Goldberg A. L. The metabolic fates of amino acids and the formation of glutamine in skeletal muscle. J Biol Chem. 1978 May 25;253(10):3685–3693. [PubMed] [Google Scholar]
  4. Chang T. W., Goldberg A. L. The origin of alanine produced in skeletal muscle. J Biol Chem. 1978 May 25;253(10):3677–3684. [PubMed] [Google Scholar]
  5. Davis E. J., Bremer J. Studies with isolated surviving rat hearts. Interdependence of free amino acids and citric-acid-cycle intermediates. Eur J Biochem. 1973 Sep 21;38(1):86–97. doi: 10.1111/j.1432-1033.1973.tb03037.x. [DOI] [PubMed] [Google Scholar]
  6. Davis E. J., Spydevold O., Bremer J. Pyruvate carboxylase and propionyl-CoA carboxylase as anaplerotic enzymes in skeletal muscle mitochondria. Eur J Biochem. 1980 Sep;110(1):255–262. doi: 10.1111/j.1432-1033.1980.tb04863.x. [DOI] [PubMed] [Google Scholar]
  7. Felig P., Pozefsky T., Marliss E., Cahill G. F., Jr Alanine: key role in gluconeogenesis. Science. 1970 Feb 13;167(3920):1003–1004. doi: 10.1126/science.167.3920.1003. [DOI] [PubMed] [Google Scholar]
  8. Garber A. J., Karl I. E., Kipnis D. M. Alanine and glutamine synthesis and release from skeletal muscle. II. The precursor role of amino acids in alanine and glutamine synthesis. J Biol Chem. 1976 Feb 10;251(3):836–843. [PubMed] [Google Scholar]
  9. Goldstein L., Newsholme E. A. The formation of alanine from amino acids in diaphragm muscle of the rat. Biochem J. 1976 Feb 15;154(2):555–558. doi: 10.1042/bj1540555. [DOI] [PMC free article] [PubMed] [Google Scholar]
  10. Harris R. A., Paxton R., DePaoli-Roach A. A. Inhibition of branched chain alpha-ketoacid dehydrogenase kinase activity by alpha-chloroisocaproate. J Biol Chem. 1982 Dec 10;257(23):13915–13918. [PubMed] [Google Scholar]
  11. Jefferson L. S., Boyd T. A., Flaim K. E., Peavy D. E. Regulation of protein synthesis in perfused preparations of rat heart, skeletal muscle and liver. Biochem Soc Trans. 1980 Jun;8(3):282–283. doi: 10.1042/bst0080282. [DOI] [PubMed] [Google Scholar]
  12. Jefferson L. S., Li J. B., Rannels S. R. Regulation by insulin of amino acid release and protein turnover in the perfused rat hemicorpus. J Biol Chem. 1977 Feb 25;252(4):1476–1483. [PubMed] [Google Scholar]
  13. KOMINZ D. R., HOUGH A., SYMONDS P., LAKI K. The amino acid composition of action, myosin, tropomyosin and the meromyosins. Arch Biochem Biophys. 1954 May;50(1):148–159. doi: 10.1016/0003-9861(54)90017-x. [DOI] [PubMed] [Google Scholar]
  14. Lee S. H., Davis E. J. Carboxylation and decarboxylation reactions. Anaplerotic flux and removal of citrate cycle intermediates in skeletal muscle. J Biol Chem. 1979 Jan 25;254(2):420–430. [PubMed] [Google Scholar]
  15. MANCHESTER K. L. OXIDATION OF AMINO ACIDS BY ISOLATED RAT DIAPHRAGM AND THE INFLUENCE OF INSULIN. Biochim Biophys Acta. 1965 Apr 12;100:295–298. doi: 10.1016/0304-4165(65)90457-5. [DOI] [PubMed] [Google Scholar]
  16. Mallet L. E., Exton J. H., Park C. R. Control of gluconeogenesis from amino acids in the perfused rat liver. J Biol Chem. 1969 Oct 25;244(20):5713–5723. [PubMed] [Google Scholar]
  17. Odessey R., Goldberg A. L. Oxidation of leucine by rat skeletal muscle. Am J Physiol. 1972 Dec;223(6):1376–1383. doi: 10.1152/ajplegacy.1972.223.6.1376. [DOI] [PubMed] [Google Scholar]
  18. Odessey R., Khairallah E. A., Goldberg A. L. Origin and possible significance of alanine production by skeletal muscle. J Biol Chem. 1974 Dec 10;249(23):7623–7629. [PubMed] [Google Scholar]
  19. Ruderman N. B., Berger M. The formation of glutamine and alanine in skeletal muscle. J Biol Chem. 1974 Sep 10;249(17):5500–5506. [PubMed] [Google Scholar]
  20. Ruderman N. B., Houghton C. R., Hems R. Evaluation of the isolated perfused rat hindquarter for the study of muscle metabolism. Biochem J. 1971 Sep;124(3):639–651. doi: 10.1042/bj1240639. [DOI] [PMC free article] [PubMed] [Google Scholar]
  21. Snell K., Duff D. A. Alanine and glutamine formation by muscle. Biochem Soc Trans. 1980 Oct;8(5):501–504. doi: 10.1042/bst0080501. [DOI] [PubMed] [Google Scholar]
  22. Snell K., Duff D. A. The release of alanine by rat diaphragm muscle in vitro. Biochem J. 1977 Feb 15;162(2):399–403. doi: 10.1042/bj1620399. [DOI] [PMC free article] [PubMed] [Google Scholar]
  23. Snell K. Muscle alanine synthesis and hepatic gluconeogenesis. Biochem Soc Trans. 1980 Apr;8(2):205–213. doi: 10.1042/bst0080205. [DOI] [PubMed] [Google Scholar]
  24. Spydevold S., Davis E. J., Bremer J. Replenishment and depletion of citric acid cycle intermediates in skeletal muscle. Indication of pyruvate carboxylation. Eur J Biochem. 1976 Dec;71(1):155–165. doi: 10.1111/j.1432-1033.1976.tb11101.x. [DOI] [PubMed] [Google Scholar]

Articles from Biochemical Journal are provided here courtesy of The Biochemical Society

RESOURCES