Response of adrenalectomized rats to chronic exercise.

Abstract

Once pilot studies had indicated that adrenalectomized rats would perform and survive repeated bouts of treadmill exercises, an 80–day training study was initiated with 16 trained and IS non—trained male rats maintained on a 0.9% saline solution. Rats were subjected to an exercise load that was progressively increased throughout the experimental period. Water tests were performed before and after the termination of the study. In addition, blood samples were obtained before sacrifice to determine 11–OCHS levels. These results indicated that the adrenal glands had been effectively removed. Resting and exercise heart rates obtained after surgery indicated an excessive response by the sympathetic nervous system. Comparisons between trained and nontrained groups showed that the trained animals had lighter body weights, less cardiac accelerations after an injection of atropine sulfate, lower exercise heart rates, higher rates from isolated hearts that were perfused with a Krebs—Henseleit solution containing iso...