THE PROLIFERATIVE ACTIVITY OF MYOCARDIAL CAPILLARY WALL CELLS IN VARIOUSLY AGED SWIMMING‐EXERCISED RATS

Abstract
Cellular proliferation was studied by incorporation of 3H‐thymidine in the hearts of young, adult and old swimming‐exercised rats. The proliferative activity was measured by scintillation counting. The swimming exercise induced a significant proliferation of capillary wall cells in the younger age groups, suggesting a neoformation of myocardial capillaries in these rats, whereas no cell proliferation was recorded in the old rats.