Effect of exercise and adrenal insufficiency on urea production in rats

  • L. Litvinova
  • A. Viru
Original Article

Abstract

Experiments on Wistar rats were designed to study the effect of exercise on urea production in the liver of intact and adrenalectomized rats. The urea production rate was assessed by the14C-urea content in liver tissue after administration of NaH14CO3. In intact rats swimming caused increases in14C-urea content in the liver compared to the resting concentrations in intact control rats: by 45% after 30 min of swimming carrying an additional load of 10% body mass by, 35% after 3 h of swimming without an additional load and by 103% after 10 h of swimming. Concentrations of urea in liver and blood were elevated simultaneously. The specific activity of14C-urea did not change significantly as a result of the exercise performed. In adrenalectomized rats the basal rate of urea production was reduced by an insignificant amount, but swimming for 3 h resulted in a decrease in liver14C-urea (by 24%). The results confirmed the exercise-induced increase in urea production and indicated as essential role for adrenal hormones in this response.

Key words

Adrenalectomy Arginase Exercise Liver Urea 

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References

  1. Baker MA, Horvath SM (1964) Influence of water temperature on oxygen uptake by swimming rats. J Appl Physiol 19: 1215–1218Google Scholar
  2. Carraro F, Kimbrough TD, Wolfe RR (1993) Urea kinetics in humans at two levels of exercise intensity. J Appl Physiol 75: 1180–1185Google Scholar
  3. Dohm GL, Hecker AL, Brown WE, Klein GJ, Puente FR, Askew EW, Beecher GR (1977) Adaptation of protein metabolism to endurance training. Increased amino oxidation in response to training. Biochem J 164: 705–706Google Scholar
  4. Dunn A, Chenoweth M, Schaeffer LD (1976) Effect of adrenalectomy on glucose turnover, the Cori cycle and gluconeogenesis from alanine. Biochem Biophys Acta 117: 11–16Google Scholar
  5. Felig P (1973) The glucose-alanine cycle. Metabolism 22: 179–207Google Scholar
  6. Greenberg DM (1955) Arginase. In: Colowick CP, Kaplan NO (eds) Methods in enzymology, vol 2. Academic Press, New York, p 368Google Scholar
  7. Haralambie G, Berg A (1976) Serum urea and amino nitrogen changes with exercise duration. Eur J Appl Physiol 36: 39–48Google Scholar
  8. Heathcote JG, Davies DM, Haworth C (1971) An improved technique for the analysis of amino acids and related compounds on the thin layers of cellulose. V. The quantitative determination of urea in urine. J Chromatogr 60: 103–109Google Scholar
  9. Karl IE, Gerber AJ, Kinnis DM (1976) Alanine and glutamine synthesis and release from skeletal muscle. III. Dietary and hormonal regulation. J Biol Chem 251: 844–850Google Scholar
  10. Lemon PWR, Mullin JP (1980) Effect of initial muscle glycogen on protein catabolism during exercise. J Appl Physiol 46: 624–629Google Scholar
  11. Leninger AL (1982) Principles of Biochemistry. Worth, New York, p 554Google Scholar
  12. Lorenz R, Gerber G (1979) Harnstoff bei körperlichen Belastungen: Veränderungen der Synthese, der Blutkonzentration und der Ausscheidung. Med Sport 19: 240–248Google Scholar
  13. Lowry OH, Rosenbrough NI, Farr AL, Randell RJ (1951) Protein measurement with the Folin phenol reagent. J Biol Chem 193: 265–275Google Scholar
  14. McArdle WD (1967) Metabolic stress of endurance swimming in the laboratory rat. J Appl Physiol 22: 50–54Google Scholar
  15. Poortmans JR (1988) Protein metabolism. In: Poortmans JRP (ed) Principles of exercise biochemistry. Karger, Basel, pp 164–193Google Scholar
  16. Saheki T, Katunuma N (1975) Analysis of regulatory factors for urea synthesis by isolated perfused rat liver. I. Urea synthesis with ammonia and glutamine as nitrogen sources. J Biochem (Tokyo) 77:659–669Google Scholar
  17. Schimke RT (1962a) Adaptive characteristics of urea cycle enzymes in the rat. J Biol Chem 237: 459–408Google Scholar
  18. Schimke RT (1962b) Differential effects of fasting and protein -free diets on levels of urea cycle enzymes in rat liver. J Biol Chem 237: 1921–1924Google Scholar
  19. Schimke RT (1963) Studies on factors affecting the levels of urea cycle enzymes in rat liver. J Biol Chem 238: 1012–1018Google Scholar
  20. Shephard RE, Gollnick PD (1976) Oxygen uptake of rats at different work intensities, Pflügers Arch 362: 219–222Google Scholar
  21. Urhausen A, Kindermann W (1992) Biochemical monitoring of training. Clin J Sport Med 2: 52–61Google Scholar
  22. Viru A (1983) Exercise metabolism and endocrine function. In: Knutten GH, Vogel JA, Poortmans JR (eds) Biochemistry of exercise. Human Kinetics Champaign. Ill., pp 76–86Google Scholar
  23. Viru A (1987) Mobilization of structural proteins during exercise. Sports Med 4: 95–128Google Scholar
  24. Viru A, Litvinova L, Viru M, Smirnova T (1994) Glucocorticoids in metabolic control during exercise: alanine metabolism. J Appl Physiol 76: 801–805Google Scholar
  25. White TP, Brooks GA (1981) /U-14C/ glucose, -alanine, and -leucine oxidation in rats at rest and two intensities of running. Am J Physiol 240: 155–165Google Scholar
  26. Wolfe RR, Goodenough RD, Wolfe MH, Royl GT, Nadel EK (1982) Isotopic analysis of leucine and urea metabolism in exercising humans. J Appl Physiol 52:458–466Google Scholar
  27. Wolfe RR, Wolfe MH, Nadel ER, Shaw JH (1984) Isotopic determination of amino acid-urea interaction in exercise in humans. J Appl Physiol 56: 221–229Google Scholar

Copyright information

© Springer-Verlag 1995

Authors and Affiliations

  • L. Litvinova
    • 1
  • A. Viru
    • 1
  1. 1.Institute of ExerciseBiology University of TartuEstonia

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