Action of Testosterone in Blocking Urinary Electrolyte Effects of Desoxycorticosterone.

Abstract

Large doses of testosterone blocked urinary electrolyte effects of desoxycorticosterone acetate (DCA) in adrenalectomized rats. The steroid reversed the Na/K response to DCA by simultaneously blocking Na retention and K loss. It did not affect Na/K in a manner opposing DCA action when given alone. These observations suggest competitive inhibition as the mechanism of effect for testosterone. Unlike progesterone, it was devoid of DCA-like effects on Na/K given alone, and it gave increasing DCA-blocking effect over a relatively wide range of doses.