The roles of angiotensin receptors in cerebral ischemia

Abstract

The main purpose of this study is to evaluate the effects of angiotensin AT1 and AT2 receptors during acute ischemic injury induced by middle cerebral artery occlusion (MCAO) in normotensive Wistar rat and spontaneous hypertensive rat (SHR). We found that TCV-116 (AT1 receptor antagonist) had more neuroprotective effects than ramipril (an angiotensin converting enzyme inhibitor) in Wistar rat and SHR. The beneficial effects of TCV-116 could be abolished by PD123319 (an AT2 receptor antagonist). We also found that TCV-116 could up-regulate the gene expression of AT2 receptor in both kinds of rats. Our results implied that AT1 and AT2 receptors might play opposite roles during cerebral injury, and both AT1 receptor antagonism and AT2 receptor activation could medicate protective effects against acute cerebral ischemia produced by MCAO.