The preventive therapeutic effect and mechamsm of neuregulin on cerebral ischemic injury in rats

doi:10.3969/j.issn.1671-2897.2008.04.008

Abstract：Objective To evaluate the preventive therapeutic effects of neuregulin-1β(NRG-1β)on ischemic cerebral insult in rats and to probe into its mechanism.Methods One hundred and C,fty healthy Wistar rats were subjected to establish middle cerebral artery occlusion(MCAO)raxtel by intraluminal thread,and randomly divided into the control and the pretreatment group.NRG-1β(2μg/kg)was adnfimstrated into the imemal candid artery (ICA)in tlle pretreatment group before MCAO.At the interval of either 0 h,0.5 h,1 h,1.5 h or2 h after MCAO operation,the brain water content was expressed as the percentage change using wet and dry weight method,and the cerebral infarction volume was detected with tetrazolium chloride(TIE)stain.The apoptosis were determined by terrmnal dcoxynueleotidyl transference-mediated biotinylated nick end labeling technique(TUNEL.)and early growth response gone-1(Esr-1)by immunohistochemical assay.Paesults After MCAO,the brain water content and the cerebral infarction volume was increased successively according to the ischemic time.NRG-1β pretreatment could decrease the two parameters compared with the control group at the same timepoint.Simultaneously,the cerebral ischemia could induce the apoptosis and expression of Egr-1 in braintissue.Withinthe duration ofischemic time,the number of apoptoticcells and Esr-1 positive cells increased gradually.NRG-1β pretreatment could obviously decnease the amount of apoptotic cells and increase the expression level of Egr-1 protein.Conclusion NRG-1β,might play a crucial neuroprotective effect in ischemic cerebral insult through inhibiting apoptosis and activating some early gene expression.