EFFECTS OF PROPOFOL ON VASCULAR SMOOTH-MUSCLE FUNCTION IN ISOLATED RAT AORTA

This study was undertaken to determine the direct actions of propofol, and whether propofol exerts any action on basal endothelium-derived r elaxing factor release and vasodilator effect of acetylcholine on phen ylephrine-induced contractile responses in isolated rat aortic rings. This compound is known to produce a fall in blood pressure in man and animals, and it has been suggested that the hypotension may result fro m a direct vasodilator action on the veins and arterioles. In this stu dy propofol did not induce any contractile response in aortic rings at various concentrations (10(-8)-10(-4) M). Propofol did not significan tly alter phenylephrine-induced contractions at lower concentrations ( 10(-8)-10(-6)M) but at higher concentrations (10(-5)-10(-4)M) the depr ession caused by propofol was significant in both endothelium-intact a nd -denuded rings. Pretreatment of the endothelium-intact rings with p ropofol (10(-6) and 10(-5) M) produced a reduction in the relaxant eff ect of acetylcholine. The results obtained in this study demonstrate t hat clinically relevant concentrations of propofol (10(-6)M or less) h ave no direct vasodilator effects and that it reduces endothelium-depe ndent relaxation to acetylcholine.