Monovalent and divalent ions in vascular tissue #MMPMID6303175
Friedman SM
Ann Intern Med 1983[May]; 98 (5 Pt 2): 753-7 PMID6303175show ga
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.
Ann+Intern+Med 1983 ; 98 (5 Pt 2): 753-7
