[Rapid autoregulatory component of cerebral vessels]

The changes of cerebral blood flow registered by means of flowmeter in the common carotid artery were investigated during fast raise and drop of arterial blood pressure in acute experiments on anesthetized cats. Both the raise and drop of arterial pressure resulted in fast autoregulatory changes of cerebral blood flow occurring even after resection of cervical sympathetic ganglia. The alpha-adrenergic blockade abolished the fast autoregulatory phase during raise of the arterial pressure. These findings sugget participation of noradrenergic mechanisms in reaction to acute hypertension.