Abstract
Summary
The acute vascular effects of elevating and reducing arterial plasma [K+] in the canine gracilis muscle and forelimb have been compared with calculated changes in the resting membrane potential of a vascular smooth muscle cell. The direction, time course, and pattern of the changes in vascular resistance and calculated resting membrane potential agree very closely. Changes in calculated membrane potential are determined primarily by the effects of changes in [K+] e and [Na+] i on the rate of active transport by the electrogenic Na-K pump. This suggests that changes in arterial plasma [K+] alter vascular resistance via the direct effect of [K+] e on the contribution of the electrogenic pump to resting membrane potential and secondarily by the effects of changes in [Na+] i . Further, the data indicate that K+ does not play a role in maintaining exercise hyperemia.
Get full access to this article
View all access options for this article.