Vascular sodium pump: endothelial modulation and alterations in some pathological processes and aging.
The vascular Na+ pump maintains intracellular ionic concentration and controls membrane potential. Its inhibition by cardiac glycosides enhances the intracellular Na+ concentration. This in turn activates the Na+-Ca2+ exchange mechanism, which induces intracellular Ca2+ increase, membrane depolarization, and noradrenaline release from perivascular adrenergic nerve endings; mechanisms that promote vasoconstriction. This article reviews the relevance of the Na+ pump in vascular tone regulation and the modulation of its activity by the endothelium. The endothelium negatively modulates the vasoconstriction elicited by Na+ pump inhibition by the release of nitric oxide, according to some authors, or an unknown factor, as suggested by others. The possible existence of endogenous digitalis-like factors is also reviewed, as is the involvement of the vascular Na+ pump in some cardiovascular disorders and aging.
Marín
J
J
Departamento de Farmacología y Terapéutica, Facultad de Medicina, Universidad Autónoma, Madrid, Spain. jesus.marin@uam.es
Redondo
J
J
D000375:Aging / Q000502:physiology*; D000818:Animals; D001808:Blood Vessels / Q000502:physiology*; D002298:Cardenolides; D003920:Diabetes Mellitus / Q000378:metabolism; D004077:Digoxin; D004730:Endothelium, Vascular / Q000502:physiology*; D006801:Humans; D006973:Hypertension / Q000209:etiology; D009569:Nitric Oxide / Q000096:biosynthesis; D009638:Norepinephrine / Q000378:metabolism; D010042:Ouabain / Q000378:metabolism; D012503:Saponins / Q000378:metabolism; D000254:Sodium-Potassium-Exchanging ATPase / Q000737:chemistry / Q000502:physiology*; D014664:Vasodilation
D002298:Cardenolides; D012503:Saponins; C034504:digoxin-like factors; D009569:Nitric Oxide; D010042:Ouabain; D004077:Digoxin; D000254:Sodium-Potassium-Exchanging ATPase; D009638:Norepinephrine