Propofol decreases arterial blood pressure. This has been ascribed to vasodilation and decreased cardiac output occuring separately or in combination. The goal of the present study was to assess the effects of propofol on the phenylephrine induced vasoconstriction in rat thoracic aortic rings.

All aortic rings were removed endothelium and isometric tension was recorded under a resting tension of 3 g. Isolated aortic rings were precontracted with phenylephrine (0.3µM) and propofol (1 to 100µM) was added cumulatively. We induced the phenylephrine preconstriction after treatment of verapamil 10µM in the other vascular rings.

Propofol (1 to 100µM) attenuated phenylephrine (0.3µM) induced preconstriction dose-dependently. The administration of propofol (1 and 10µM) did not change the tonic constriction. The contractile response were significantly attenuated in verapamil pretreated rings but propofol did not affect on constriction in all dose range.

Propofol attenuated phenylephrine precontracted rat thoracic aortic rings with inhibition of Ca²⁺ movement through the L-type calcium channel in the sarcolemmal membrane.