Effects of propofol on isolated rat aorta and the possible mechanisms

Objective To investigate the effects of propofol on the isolated rat aorta to explore the relationship between propofol and ATP-sensitive K + channel(K ATP ) and the mechanisms. Methods The effects of propofol and DMSO on norepinephrine (NE)-induced vasoconstriction were determined in the isolated rat aortic rings under varied circumstances:in calciferous or noncalciferous K-H solutions,with or without intact endothelium,in the presence or absence of glibenclamide(the specific antagonist of K ATP ). Results DMSO showed no obvious effects in all of the experimental conditions. Propofol at 100 μg·ml -1 dilated the NE-pretreated aorta by 58%(P0.01). This effect was also observed in noncalciferous solution and in ex-endothelium condition,and could be partially antagonised by glibenclamide(P0.01).Conclusions The vasodilatory effect of propofol on isolated rat aortic rings is related to the modulation of K ATP ,through which the extracellular Ca 2+ influx and/or the release of intracellular Ca 2+ are depressed. The drug acts directly on the vascular smooth muscle,which may be independent of intact endothelium and extracellular Ca 2+ .