The effect of exercise on cell proliferation in the non-ischemic heart after myocardial infarction.

The influence of physical training (180 hours, 3 hours per day) on the 3H-thymidine incorporation into the connective tissue cell nuclei and into the myocardial cell nuclei of the non-ischemic heart after myocardial infarction was studied in 38 untrained and trained male Wistar rats. In the connective tissue cells physical training caused a clearly reduced proliferative activity which could be demonstrated until the seventh day after infarction. Besides, in trained animals there was a decreased DNA turnover of the heart muscle cells during the first few days following myocardial infarction. Probably, the observed changes are an expression of the different adaptability of the untrained and trained non-ischemic myocardium.