The specific angiotensin receptor antagonist [Sar1, Thr8]AII (sarthran) was intracerebroventricularly (ICV) infused in anesthetized spontaneously hypertensive rats (SHR) and Wistar-Kyoto (WKY) normotensive controls. The results extend earlier findings by determining that: 1) the hypotensive effect of ICV-infused sarthran could be enhanced in anesthetized as compared with alert animals; 2) SHRs revealed a greater hypotensive response as compared with WKY rats; and 3) no sarthran-induced agonistic effects were observed in contrast with previous results using alert SHRs. These findings support the use of sarthran as a potent angiotensin receptor antagonist to investigate the role of the brain angiotensin system in the control of normal and dysfunctional blood pressure.