Effect of endothelin-1 on DNA synthesis in the myocardium of albino rats during early postnatal ontogeny.

Effect of intraperitoneal injection of endothelin-1 on DNA synthesis in the myocardium of newborn albino rats was studied by(3)H-thymidine autoradiography. Endothelin-1 injected in a single dose of 10 microg/kg stimulated proliferative processes: the index of labeled nuclei and labeling intensity increased. Repeated (5 times) administration of endothelin-1 in doses of 1 and 10 microg/kg increased labeling intensity, but did not change the index of labeled nuclei. The data suggest that endothelins are involved in morphogenesis of the myocardium during the early postnatal ontogeny.