Positive and negative adaptation of muscle enzymes in aging mice subjected to physical exercise.

CWI mice at the age of 6, 22 and 27 months were subjected to a controlled physical training program for 5 weeks. Changes in specific activity of the enzymes aldolase, superoxide dismutase and catalase of the total hind-leg muscle tissues were followed. During the training period, specific activities of these muscle enzymes exhibited an adaptive increase in the 6 and 22 months groups. In senile (27 months) mice, however, enzyme activities decreased as a consequence of the physical challenge. Total body weight was not altered under these conditions. Immunotitration of extracts with anti-aldolase and anti-creatine kinase antibodies showed no significant differences, indicating that there was no accumulation of disappearance of faulty proteins during aging and physical exercise.