Action of Testosterone in Blocking Urinary Electrolyte Effects of Desoxycorticosterone. ∗

Abstract

Summary

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.