Capillary proliferative activity in myocardium and skeletal muscle of exercised rats

J Appl Physiol Respir Environ Exerc Physiol. 1977 Aug;43(2):306-7. doi: 10.1152/jappl.1977.43.2.306.


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.

Publication types

  • Comparative Study

MeSH terms

  • Animals
  • Autoradiography
  • Body Weight
  • Capillaries / physiology*
  • Cell Division
  • Coronary Vessels / physiology*
  • Female
  • Hypertrophy
  • Muscles / blood supply*
  • Physical Exertion*
  • Rats
  • Thymidine / metabolism


  • Thymidine