THE EFFECT OF ENDOTHELIUM ON THE RESPONSE TO PROPOFOL ON BOVINE CORONARY-ARTERY RINGS

In this study the effect of propofol on isolated bovine coronary arter y tone was studied in artery rings precontracted with PGF(2 alpha). Pr opofol, in concentrations of 10(-6)-10(-5) M did not change vascular s mooth muscle tone, but at high concentrations (10(-4)10(-1) M) produce d relaxation in rings with intact endothelium. In rings denuded of end othelium or treated with methylene blue, propofol produced relaxation at 10(-3)-10(-1) M concentrations, but there was a significant decreas e in relaxation compared to endothelium intact rings. In the presence of a calcium agonist (Bay K 8644; 10(-5) M), propofol produced constri ction in rings denuded of endothelium. These results suggest that high concentrations of propofol may hale vasorelaxant effect on bovine cor onary artery and that these effects may be due to actions on the endot helium and mediated by calcium channels.