[The sodium-potassium pump in hypertension. Mechanisms of action of potassium].

Increasing evidence indicates that sodium ingestion in the face of an inability to excrete it normally causes hypertension by releasing a humoral pressor substance. This substance, which is probably the putative natriuretic hormone, inhibits Na+-K+-ATPase and thereby increases cardiac contractility and blood vessel tone. Potassium may be antihypertensive in part by virtue of its ability to stimulate Na+-K+-ATPase in the vascular smooth muscle cells and in adrenergic nerve endings, thereby causing vasodilation.