Monovalent and divalent ions in vascular tissue.
Steep transmembrane concentration gradients in vascular smooth muscle for all ions are maintained by energy-requiring pumps. The Na+ gradient appears to dominate the distribution of the other ions primarily because it controls cell hydration and energizes the transport of sugars, amino acids, and Ca++, Mg++, and H+. The Na+ gradient is a closely regulated constant (about ten to one) and is not perturbed except by changes in the limited permeability of the vascular smooth muscle membrane to Na+ or in the activity of its transport enzyme, the Na+-K+ATPase. Increased permeability to Na+ has been seen in vascular smooth muscle and in erythrocytes in salt-dependent forms of experimental hypertension, as well as in essential hypertension. A compensatory increase in Na+ transport (extrusion) has been seen. This increase in transport can be produced by a moderate increase in aldosterone acting alone or by a lesser increase acting synergistically with vasopressin.
D000818:Animals; D001158:Arteries / Q000378:metabolism; D002118:Calcium / Q000378:metabolism; D006973:Hypertension / Q000378:metabolism; D007473:Ion Channels / Q000378:metabolism*; D008274:Magnesium / Q000378:metabolism; D009131:Muscle, Smooth, Vascular / Q000378:metabolism*; D011188:Potassium / Q000378:metabolism; D051381:Rats; D012964:Sodium / Q000378:metabolism
D007473:Ion Channels; D012964:Sodium; D008274:Magnesium; D011188:Potassium; D002118:Calcium