[Mechanism of the diuretic action of epiphyseal extracts]

Experiments on dogs demonstrated that intravenous administration of the epiphysis extracts prevented the antidiuretic action of both the endogenous (traumatic stress) and exogenous (pituitrin) antidiuretic hormone (ADH). Injection of the extract into the renal artery gave a unilateral diuretic effect. The diuretic action of the preparation was eliminated by the block of the alpha-adrenergic receptors, whereas beta-adrenoblockers were ineffective. A conclusion was drawn that the mechanism of the diuretic action of the epiphysis extracts consisted in the competitive suppression of the ADH action at the renal tubules level on account of excitation of the alpha-adrenoceptors and inhibition of the adenylcyclase activity.