The effects of terminating and detraining on enzyme activities of heart and skeletal muscle of trained rats

Summary

Thirty-six male Sprague-Dawley rats with an average beginning weight of 360 grams were trained for 5 weeks with an exercise program consisting of swimming for 35 minutes a day in water at 35 ° C. At the end of this training period one of the trained groups terminated the exercise program, while the remaining experimental group of animals detrained by swimming a minute less each day for 5 weeks following the training.

Control-fed non-swimming animals served as controls.

The group of animals that terminated the training program gained weight at a rate which was about 60% greater than the controls. The detrained group of animals had adrenals that were significantly heavier (P < 0.05) than the controls while their kidney weights were significantly lighter (P < 0.05).

Aldolase, cytochrome oxidase and succinate-cytochromec reductase activities were determined for both the heart ventricles and gastrocnemii. The results were expressed in terms of unit and total activities.

The termination of training significantly changed the succinate-cytochromec reductase activities of the skeletal muscle (P < 0.05), while the cytochrome oxidase activities and the unit activity of succinate-cytochromec reductase of the heart ventricles were significantly altered (P < 0.05) for the detrained group.

Aldolase revealed no significant enzymatic changes in either heart or skeletal muscle for either of the experimental groups.