[Effect of verapamil on cerebral circulation].

Acute experiments were conducted on anesthetized cats; verapamil in a dose of 0.05, 0.1, 0.5, and 1 mg/kg, injected intravenously, caused a reduction of the tone of the cerebral vessels and of the general arterial pressure. Changes in the volume velocity of the cerebral circulation were phasic in character and depended on the tone of the cerebral vessels and the arterial pressure level. The circulation increased more in the cerebral cortex than in the reticular formation; PO2 correlated with the circulation in the cerebral cortex. The diameter of the pial arteries became greater both in case of the intravascular verapramil administration and its local application. The block of beta-adrenoceptors, M-cholinoreceptors, histamine receptors and preliminary administration of the sympatholytic failed to eliminate the vasodilatory action of verapamil. It is supposed that vasodilation was myotropic in character, and was possible connected with the electrolyte metabolism.