title: Capillary proliferative activity in myocardium and skeletal muscle of exercised rats.
abstract: The capillary proliferative activity in heart and skeletal muscle was studied by autoradiography after in vivo injections of [3H]thymidine in swimming exercised rats. Swimming exercise led to hypertrophy of the myocardium and the muscle fibers of the fore- and hindlimbs. When compared with normal controls a highly significant increase in nuclear incorporation of [3H]thymidine was found in the cells of the myocardial capillary walls. No increased incorporation of [3H]thymidine was found in capillary wall cells of fore- and hindlimb muscles. The findings confirm previous observations of a significant neoformation of myocardial capillary blood vessels in swimming-induced cardiac hypertrophy, whereas any capillary neoformation in the hypertrophying skeletal muscles of this experimental model is insignificant.
mesh_terms: D000818:Animals; D001345:Autoradiography; D001835:Body Weight; D002196:Capillaries / Q000502:physiology*; D002455:Cell Division; D003331:Coronary Vessels / Q000502:physiology*; D005260:Female; D006984:Hypertrophy; D009132:Muscles / Q000098:blood supply*; D005082:Physical Exertion; D051381:Rats; D013936:Thymidine / Q000378:metabolism
chemical_list: D013936:Thymidine