The area postrema and the hypertensive effect of angiotensin.

The intracerebroventricular administration of angiotensin II in pentobarbital-anesthetized cats produced dose-dependent increases in the arterial blood pressure without significant changes in the heart rate. The ablation of the area postrema significantly reduced, but did not abolish, the pressor effect of angiotensin injected into the cerebral ventricles. It follows, then, that the central pressor effect of angiotensin is dependent on the integrity of the area postrema and that this central site, at least in part, contributes to the pressor action of endogenous angiotensin.