The effect of exhaustive swimming and chloramphenicol on the content of mitochondrial protein and cytochromes in rat liver and myocardium.

The content of mitochondrial protein and cytochromes aa3, b, c1 and c in rat liver and heart was determined in four groups of rats: controls, CAP-treated rats, exercised rats and CAP-treated exercised rats. Single swimming does not change the amount of mitochondrial protein in liver and myocardium as well as the content of cytochromes aa3, b, c1 and c in liver mitochondria. The content of cyt. c is lowered in heart mitochondria. CAP treatment of rats for three days decreases the amount of mitochondrial proteins and cyt. aa3, and b whereas no such changes are observed in heart mitochondria. The subsequent swimming on the background of the inhibitor does not affect additionally liver mitochondria, but lowers significantly the mitochondrial protein and the content of cyt. aa3, b, c1 and c in the myocardium. These data show that exhaustive muscular work alters the effect of CAP in heart mitochondria. Three hours of exhaustive swimming are not sufficient to change neither the amount of total mitochondrial protein, nor the cytochrome content. The lowered cyt. c content in heart mitochondria after swimming is explained by an intensified permeability of the outer membrane. Thus, the changes in the activity of some enzymes and the oxidative phosphorylation previously reported by us, are not due to alterations in the protein synthesis.