Changes of rennin-angiotensin system in rats with focal brain ischemia-reperfusion injury and the effects of intervention with Irbsartan / 临床神经病学杂志

ABSTRACT

Objective To explore the changes of rennin-angiotensin system in rats with focal brain ischemia-reperfusion injury and the effects of intervention and neuroprotective mechanisms with Irbsartan. Methods The male SD rats were randomly assigned to sham operated group, ischemia-reperfusion (IR) group and Irbsartan pretreatment group. The focal IR model was made by suture occlusion of right middle cerebral artery (MCAO). At 24 h and 72 h following onset of MCAO with reperfusion,the neurologic impairment function scores and the infarction volume were evaluated, the mRNA expression of angiotensinⅡ type 1 receptor (AT1R) and angiotensinⅡ type 2 receptor(AT2R)were detected by RT-PCR, and AngⅡ levels and Renin activity were examined by radioimmuno-assay. Results (1) Pretreatment with Irbsartan could significantly improve neurological outcome and reduced infarction size. (2) In bilateral cerebral cortex, hypothalamus, brain stem and peripheral blood leucocyte, the mRNA expressions of the AT1R and AT2R were significantly increased after either 24 h or 72 h of MCAO with reperfusion (all P