A Possible Mechanism of Endothelium-dependent Relaxation Induced by Pirarubicin and Carbachol in Rat Isolated Aorta

Publisher Website
Google Scholar
Abstract
The mechanism of endothelium-dependent relaxation induced by pirarubicin, (2″R)-4′-O-tetrahydropyranyladriamycin, THP, or carbachol was investigated in the rat isolated aorta. The relaxant effect of THP (1·5 × 10−6-4·5 × 10−5 m) or carbachol (10−8-10−4 m) on the aorta with endothelium was decreased by lowering Ca2+ in the medium. The relaxation induced by THP was not inhibited by pretreatment with verapamil (10−6–10−5 m), and that induced by carbachol was only partially inhibited. However, on replacement of all but 20 Mm Na+ with either Li+ or choline, the THP- or carbachol-induced relaxation was inhibited. Furthermore, the relaxing effect of THP or carbachol was inhibited by pretreatment with amiloride (10−4-3 × 10−4 m), with ouabain (10−4-10−3 m), or with K+-depletion. These results suggest that the THP- or carbachol-induced relaxation depending on endothelium was affected by modifying the calcium ion concentration, and that a Na+–Ca2+ exchange process is involved.

This publication has 26 references indexed in Scilit: