[The blocking effect of adrenaline on the thyroid-stimulating effect of vasopressin in rats]

Effect of various doses of oxytocin, vasopressin or adrenalin on the thyroid gland activity was studied in hypophysectomized and nonoperated rats 20 minutes after a single injection of the neurohormones. The minimal applied dose of the neurohormones stimulated increasing of their concentration in blood up to level typical for stress reaction. Injection of oxytocin led to no effect at any dose. In nonoperated rats vasopressin stimulated the thyroid gland but did not influence on TSH level in blood. In hypophysectomized rats thyrostimulating effect of vasopressin was also detected need. Adrenalin injection inhibited the thyroid gland function in both nonoperated and hypophysectomized rats. Effect of adrenalin in combination with vasopressin was like the action of adrenalin alone. Thus, it is possible to assume that under stress conditions a high blood level of adrenalin attenuates thyrostimulating effect of vasopressin.