title: The science behind hyponatremia and its clinical manifestations.
abstract: Body sodium, water, and extracellular fluid volume are tightly regulated by neural, humoral, and renal mechanisms to maintain osmolality in extracellular fluid and to maintain normal intravascular volume. This is accomplished by controlling sodium content in extracellular fluid. In the normal physiologic state, total body water (which accounts for ~60% of body weight) is distributed among three compartments: intracellular, interstitial, and intravascular spaces. About two thirds of total body water is intracellular fluid. Potassium is the major intracellular cation, and sodium is the major extracellular cation. Body water content and plasma osmolality are tightly regulated by the action of arginine vasopressin on renal tubules. A wide variety of disease states are associated with a nonosmotic response of arginine vasopressin, also known as the antidiuretic hormone. Determination of the serum sodium concentration is the most direct measure of hyponatremia. The vasopressin V(2)-receptor antagonists are effective aquaretic agents and correct hyponatremia in several hyponatremic disorders.
authors.affiliation: Division of Renal Diseases and Hypertension, University of Colorado Denver, Aurora, Colorado 80045, USA. Robert.Schrier@ucdenver.edu
authors.forename: Robert W
authors.initials: RW
authors.lastname: Schrier
mesh_terms: D000818:Animals; D065092:Antidiuretic Hormone Receptor Antagonists; D051399:Aquaporin 2 / Q000378:metabolism; D001127:Arginine Vasopressin / Q000378:metabolism; D006801:Humans; D007010:Hyponatremia / Q000188:drug therapy / Q000209:etiology / Q000378:metabolism* / Q000628:therapy*; D017483:Receptors, Vasopressin / Q000378:metabolism; D014882:Water-Electrolyte Balance / Q000187:drug effects
chemical_list: D065092:Antidiuretic Hormone Receptor Antagonists; D051399:Aquaporin 2; D017483:Receptors, Vasopressin; D001127:Arginine Vasopressin