[Role of vasopressin and aldosterone in the mechanism of osmoregulating reaction].

Possible mechanisms responsible for a natriuretic response to NaCl hypertonic solution (515 mmol/l) digestively administered were studied in chronic experiments on Wistar and Brattleboro rats with continuously implanted urinary bladder catheters. The administration of the solution resulted in rapid antidiuresis and marked natriuresis though the plasma levels of N+ remained unchanged throughout the experiment. Natriuresis did not differ in the Brattleboro and Wistar rats. The time course of blood aldosterone was examined in experiments on Wistar rats. There was its double statistically significant decrease. It is suggested that in addition to secretion of hypophyseal neuropeptides there are additional reflex mechanisms that modulate natriuresis in osmotic irritation of the liver and that these mechanisms may trigger a decrease in plasma aldosterone levels.