The nephrotoxicity risk in rats subjected to heavy muscle activity

When the body is exposed to insults, the kidneys exhibit adap-tive changes termed renal cytoresistance, characterized by cho-lesterol accumulation in the membranes of the tubule cells. However, heavy muscle activity has not yet been accepted as one of the stressors that could lead to cytoresistance. In order to study the renal functional characteristics of animals exposed to heavy muscle activity, rats were subjected to exhaustive tread-mill exercise for 5 days and their data was compared to those of sedentary controls. It was found that in exercised rats, blood lactate, muscle citrate synthase and proximal tubule peroxyni-trite levels were all elevated, suggesting the presence of oxida-tive stress in the proximal tubule segments. However, mean arterial pressure, renal blood flow, glomerular filtration rate, fractional excretion of sodium and potassium, and organic anio