[Role of adrenergic mechanisms in the development of cerebrovascular disorders in acute myocardial ischemia].

Acute experiments were made on cats to study the general and local cerebral blood flow, the cerebrovascular tone and systemic hemodynamics during acute myocardial ischemia. Occlusion of the coronary artery resulted in the reduction of the blood flow in the carotid artery and brain cortex, decreased arterial pressure, and the cardiac output. Short-term vasodilatation was replaced by prolonged vasoconstriction which increased during myocardial ischemia. The blockade of beta-adrenoreceptors with propranolol reduced vasoconstriction. The blockade of alpha-adrenoreceptors removed or distorted vasoconstriction of the brain and hind limb vessels. The mechanisms by which brain circulatory disorders occur are discussed.