When angiotensin II is injected into the cerebral ventricles of the rat, drinking and a short latency pressor response are produced. The pressor response has 2 components. The 1st component is always associated with angiotensin injections. The 2nd component is associated with drinking behavior. If water is not available, the 2nd pressor component is absent. The drinking-associated pressor response is not only seen when angiotensin is the stimulus, but also in normal or carbachol-induced drinking. The effect is not due to head position during drinking or hypoxia but it is mediated by the sympathetic nervous system since it is abolished by alpha-adrenergic blockage.