Evidence for glucocorticoid regulation of the rat vasopressin V-1a receptor gene

WRK-1 cells express vasopressin V-1a receptors. Twenty-four-hour treatment of these cells with dexamethasone (DEX) resulted in an increase in [H-3]AVP binding that was maximal at 12 h, and could be blocked by addition of RU 38486. The increases in [H-3]AVP binding were paralleled by increases in V-1a receptor mRNA. The in vivo effects of glucocorticoids (GCs) on V-1a receptor binding in hepatic tissue were also investigated in adrenalectomized and hormone-replaced rats given either DEX or aldosterone (ALDO). DEX effectively increased V-1a receptor binding site density whereas ALDO had no effect. The DEX effects on V-1a receptor mRNA and binding strongly implicate glucocorticoids in the regulation of V-1a receptor gene expression.