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Published on: August 18, 2014
Long-term regulation of urinary concentrating capacity
1Laboratory of Kidney and Electrolyte Metabolism, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, Maryland 20892-1603, USA.
Abstract:
Urinary concentrating capacity is regulated in part by a long-term adaptational process involving changes in the absolute abundance of the aquaporin-2 water channel in collecting duct cells. Alterations in aquaporin-2 abundance play key roles in the pathophysiology of several water balance disorders. Escape from the antidiuretic action of vasopressin, e.g. in the syndrome of inappropriate antidiuretic hormone secretion, involves a selective downregulation of aquaporin-2 expression. Excessive water retention causing hyponatremia in volume-expanded states such as congestive heart failure appears to be due in part to a failure of this escape mechanism.
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