Effects of alpha and beta adrenolytic agents on the changes in arterial pressure induced by intrahypothalamic injection of carbachol and nicotine.

In order to elucidate some aspects of cholinergic and adrenergic interaction in the dorsomedial nucleus of the hypothalamus and its effect on systemic arterial pressure, carbachol and nicotine were injected into this area alone or preceded by regitine and propranolol. Both carbachol and nicotine induced hypotensive effects in normotensive anesthetized rats. Previous application of 20, 40, 80 and 160 nmol propranolol did not alter the hypotension induced, but doses of 20, 40 and 80 nmol regitine gradually attenuated the hypotensive effects of carbachol and nicotine.