AJP - Renal Physiology, Vol 253, Issue 1 164-F169, Copyright © 1987 by American Physiological Society
Insulin-stimulated protein metabolism in chronic azotemia and exercise
T. A. Davis, S. Klahr and I. E. Karl
To determine whether training reduces the acute catabolic stress of an
exercise bout, control and azotemic rats, either exercise trained or
untrained, were subjected to a bout of exercise or allowed to rest. Protein
turnover was measured immediately following exercise in isolated muscles.
Azotemia (no exercise) increased protein degradation; acute exercise (no
azotemia) decreased protein synthesis. Protein catabolism was greatest in
acutely exercised azotemic rats. Training reduced azotemia-induced and
acute exercise-stimulated increase in protein degradation. To determine
whether this improvement in protein metabolism by training was due to
increased insulin sensitivity, the dose-response to insulin was determined.
Resistance of protein synthesis or degradation to insulin was not observed
in azotemic rats. Either acute exercise or training increased sensitivities
of protein degradation and synthesis to insulin; training also increased
responsiveness of protein degradation to insulin. Thus exercise training
reduced the elevated muscle protein catabolism due to azotemia and/or acute
exercise and enhanced the action of insulin on muscle.
