Effects of Cardiac Work and Leucine on Protein Turnover

  • B. Chua
  • D. L. Siehl
  • E. O. Fuller
  • H. E. Morgan


The purpose of these experiments was to assess effects of cardiac work and leucine in hearts supplied only glucose or substrate and hormone mixtures that simulated plasma. Rates of protein degradation greatly exceeded protein synthesis in Langendorff preparations supplied glucose. This severely negative nitrogen balance was brought closer to zero by provision of more complete substrate mixtures. Cardiac work further improved the nitrogen balance by stimulating protein synthesis in hearts supplied glucose (mixture 1), glucose-insulin-glucagon-lactate-β-hydroxybutyrate (mixture 2), or palmitate-β-hydroxybutyrate-glucose (mixture 3) and inhibiting protein degradation in hearts supplied glucose. Cardiac work did not affect the rates of either protein synthesis or degradation in hearts provided insulin-lactate-glucose (mixture 4). The increase in protein synthesis was associated with increased rates of peptide chain initiation. Addition of 1 mM leucine had an additional effect to restore nitrogen balance to zero or to achieve positive balance in working hearts supplied substrate and hormone mixture 2.


Protein Synthesis Protein Degradation Protein Turnover Nitrogen Balance Substrate Mixture 
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  1. 1.
    Buse, M. G., Atwell, R., and Mancusi, V. 1979. In vitro effect of branched chain amino acids on the ribosomal cycle in muscles of fasted rats. Horm. Metab. Res. 11:289–292.Google Scholar
  2. 2.
    Chua, B., Siehl, D. L., Fuller, E. O., and Morgan, H. E. 1980. Branch chain amino acids and protein turnover in heart. In: Fourth USA-USSR Symposium on Myocardial Metabolism, pp. 305–324. U.S. Dept. of Health and Human Services (NIH Publication No. 80–2017), Bethesda.Google Scholar
  3. 3.
    Chua, B. L., Siehl, D. L., and Morgan, H. E. 1979. Effect of leucine and metabolites of branched-chain amino acids on protein turnover in heart. J. Biol. Chem. 254:8358–8362.PubMedGoogle Scholar
  4. 4.
    Chua, B., Siehl, D. L., and Morgan, H. E. 1980. A role for leucine in the regulation of protein turnover in working rat hearts. Am. J. Physiol. 239:E510–E514.PubMedGoogle Scholar
  5. 5.
    Chua, B., Watkins, C., Siehl, D. L., and Morgan, H. E. 1978. Effect of epinephrine and glucagon on protein turnover in perfused rat heart. Fed. Proc. 37:540.Google Scholar
  6. 6.
    Hems, R., Ross, B. D., Berry, M. N., and Krebs, H. A. 1966. Gluconeogenesis in the perfused rat liver. Biochem. J. 101:284–292.PubMedGoogle Scholar
  7. 7.
    Hjalmarson, Å. C., and Isaksson, O. 1972. In vitro work load and rat heart metabolism. I. Effect of protein synthesis. Acta Physiol. Scand. 86:126–144.PubMedCrossRefGoogle Scholar
  8. 8.
    Hjalmarson, Å. C., and Isaksson, O. 1972. In vitro work load and rat heart metabolism. IV. Effect on ribosomal aggregation. Acta Physiol. Scand. 86:342–352.PubMedCrossRefGoogle Scholar
  9. 9.
    Kao, R., Rannels, D. E., Whitman, V., and Morgan, H. E. 1978. Factors accounting for growth and atrophy of the heart. In: T. Kobayashi, Y. Ito, and G. Rona (eds.), Recent Advances in Studies on Cardiac Structure and Metabolism. Vol. 12: Cardiac Adaptation, pp. 105–113. University Park Press, Baltimore.Google Scholar
  10. 10.
    Lamprecht, W. I., and Trautschold, I. 1965. Determination with hexokinase and glucose-6-phosphate dehydrogenase. In: H. U. Bergmeyer (ed.), Methods of Enzymatic Analysis, pp. 543–551. Academic Press, New York.Google Scholar
  11. 11.
    McKee, E. E., Cheung, J. Y., Rannels, D. E., and Morgan, H. E. 1978. Measurement of the rate of protein synthesis and compartmentation of heart phenylalanine. J. Biol. Chem. 253:1030–1040.PubMedGoogle Scholar
  12. 12.
    Millward, D. J. 1980. Protein turnover in skeletal and cardiac muscle during normal growth and hypertrophy. In: K. Wildenthal (ed.), Degradation Processes in Heart and Skeletal Muscle, pp. 161–199. Elsevier/North Holland Biomedical Press, Amsterdam.Google Scholar
  13. 13.
    Morgan, H. E., Chua, B. H. L., Fuller, E. O., and Siehl, D. L. 1980. Regulation of protein synthesis and degradation during in vitro cardiac work. Am. J. Physiol. 238:E431–E442.PubMedGoogle Scholar
  14. 14.
    Morgan, H. E., Earl, D. C. N., Broadus, A., Wolpert, E. B., Giger, K. E., and Jefferson, L. S. 1971. Regulation of protein synthesis in heart muscle. I. Effect of amino acid levels on protein synthesis. J. Biol. Chem. 246:2152–2162.PubMedGoogle Scholar
  15. 15.
    Morgan, H. E., Jefferson, L. S., Wolpert, E. B., and Rannels, D. E. 1971. Regulation of protein synthesis in heart muscle. II. Effect of amino acid levels and insulin on ribosomal aggregation. J. Biol. Chem. 246:2163–2170.PubMedGoogle Scholar
  16. 16.
    Neely, J. R., Liebermeister, H., Battersby, E. J., and Morgan, H. E. 1967. Effect of pressure development on oxygen consumption by isolated rat heart. Am. J. Physiol. 212:804–814.PubMedGoogle Scholar
  17. 17.
    Rannels, D. E., Hjalmarson, Å. C., and Morgan, H. E. 1974. Effects of non-carbohydrate substrates on protein synthesis in muscle. Am. J. Physiol. 226:528–539.PubMedGoogle Scholar
  18. 18.
    Rannels, D. E., Kao, R., and Morgan, H. E. 1975. Effect of insulin on protein turnover in heart muscle. J. Biol. Chem. 250:1694–1701.PubMedGoogle Scholar
  19. 19.
    Schreiber, S. S., Briden, K., Oratz, M., and Rothschild, M. A. 1966. Protein synthesis in the overloaded heart. Am. J. Physiol. 211:314–318.PubMedGoogle Scholar
  20. 20.
    Schreiber, S. S., Oratz, M., Evans, C., Reff, F., Klein, I., and Rothschild, M. A. 1973. Cardiac protein degradation in acute overload in vitro. Reutilization of amino acids. Am. J. Physiol. 224:338–345.PubMedGoogle Scholar
  21. 21.
    Sherwin, R. S. 1978. Effect of starvation on the turnover and metabolic response to leucine. J. Clin. Invest. 61:1471–1481.PubMedCrossRefGoogle Scholar
  22. 22.
    Taegtmeyer, H., Hems, R., and Krebs, H. A. 1980. Utilization of energy-providing substrates in the isolated working rat heart. Biochem. J. 186:701–711.PubMedGoogle Scholar
  23. 23.
    Zak, R., Martin, A. F., Reddy, M. K., and Rabinowitz, M. 1976. Control of protein balance in hypertrophied cardiac muscle. Circ. Res. 38(Suppl. 1): 145–150.Google Scholar

Copyright information

© Springer Science+Business Media New York 1983

Authors and Affiliations

  • B. Chua
    • 1
  • D. L. Siehl
    • 1
  • E. O. Fuller
    • 1
  • H. E. Morgan
    • 1
  1. 1.Department of Physiology, The Milton S. Hershey Medical CenterThe Pennsylvania State UniversityHersheyUSA

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