ABSTRACT
Vascular smooth muscle can contract independent of membrane potential change. All vascular smooth muscle cells maintain a membrane potential negative to the outside environment. Since the size of the vascular smooth muscle cells is very small, recording of the cellular potential from these cells is extremely difficult. Abnormality in the vascular smooth muscle membrane has been implicated in many forms of experimental hypertension. Since vasoconstriction can be regulated by membrane potential directly or indirectly, it follows that changes in the resting membrane potential may be a factor in the pathogenesis of hypertension. Perhaps the most important promise in future electrophysiological study of changes in membrane properties in hypertension involves the study of isolated single smooth muscle cells. In many cell systems, the resting membrane potential is determined primarily by potassium since the membrane permeability to other ions is very low.
