Membrane Potentials of Smooth Muscle Cells of Isolated Resistance Vessels 1

Abstract

Summary

The microelectrode technique was used to measure membrane potentials from branches of the saphenous and deep caudal epigastric arteries supplying skeletal muscle and of the superior mesenteric artery of rats and guinea pigs. We found no significant differences in membrane potentials of cells from the different sources. Although KCl and epinephrine produced some depolarization of this vascular smooth muscle, the magnitude of the depolarization did not appear to reflect the magnitude of the contractile response and there was no suggestion of a spike discharge; activation of the contraction produced by these agents must be initiated through a nonelectrical pathway.