Central effects of a specific angiotensin receptor antagonist, sarthran (Sar1, Thr8AII) in normotensive and spontaneously hypertensive rat strains.

The specific angiotensin receptor antagonist, Sar1, Thr8AII (sarthran), was infused intracerebroventricularly in alert spontaneously hypertensive rats (SHR), and Wistar-Kyoto (WKY) and Sprague-Dawley (SD) normotensive rat strains. This resulted in a mean decrease of 35 mm Hg in the SHR group by 25 min post-infusion, and corresponding decreases in the WKY and SD rats of 13 and 15 mm Hg, respectively. A prominent transient sarthran-induced elevation in blood pressure was noted in the SHR group during the 5-min infusion. This agonistic effect was not observed in members of the WKY and SD strains. These data encourage the use of sarthran as a valuable pharmacological probe in the examination of the role of the brain renin-angiotensin system in hypertension.