[Effect of adrenoblockaders on vascular reactions in sinocarotid baroreflexes]

Blood pressure in the common carotid artery, the tone of the cerebral and femoral vessels were recorded by resistography in acute experiments on nonanesthetized cats (local anesthetics, listenon) with artificial respiration. The increased pressure in isolated carotid sinuses was accompanied by a decrease in arterial pressure and in the tone of the cerebral and femoral vessels. In both cases the reaction of the cerebral vessels was less pronounced as compared to that shown by the femoral vessels. The blocking of alpha-adrenoreceptors with phentolamine reduced or abolished completely the reactions noted. After beta-adrenergic blockade with obsidan these reactions persisted. The role of carotid baroceptors in the regulation of cerebral circulation under orthostatic collapse is discussed.