Tanshinone Iia Induced By Pretreatment Of Endogenous Neuroprotective Effects Of Hsp70 And Tnf-alpha Mrna Expression,

Objective To investigate the influence of Tanshinone precondition -ing on the Infarct volume,the quantity of nissl body,the expression of heat shock protein 70 and TNF-αmRNA.To approach the Tanshinone's endogenous neuroprotectant effect and its mechanisms.Methods In this study,Ischemic preconditioning(IP) was induced by intraluminal filament middle cerebral artery for 10 min.Middle cerebral artery occlusion(MCAO) was induced by intraluminal filament for 2h after IP 72h.120SD rats were included and randomly divided into 6 groups:MCAO group received 2h MCAO followed by 22h reperfusion before 3 days NS administration through peritoneal injection,IP group received 2h MCAO followed by 22h reperfusion with IP,DY group received 2h MCAO followed by 22h reperfusion before 3 days Tanshinone administration through peritoneal injection,DZ group received 2h MCAO followed by 22h reperfu -sion with Tanshinone administration through peritoneal injection once for 3 days,SS group only was exposured and segregated common carotid artery and internal carotid artery twice interval 3 days.KB group did not treat.Each group was 20 SD rats.The SD rats were killed at 22h perfusion end point.The neurologic deficit score,infarct volume,histopatholog -ical changes with HE staining under a microscopy,nissl body by using Nissl staining,the expression of HSP-70 by using immunohistochemistry method and that of TNF-αmRNA by using RT-PCR were evaluated in each group.Results①The neurologic deficit scores and the infarct volume of the IP group,the DY group and DZ group were significantly reduced than that of the SS+MCAO group(P＜0.05).The nissl body's IOD value of DY group was more significantly than in the SS+MCAO group(P＜0.05)and less than in IP group and the DZ group(P＜0.05)The pathological change was severe detected in the brain of SS+MCAO group,and moderate detected in the brain of DY group,and mild detected in the brain of IP group and DZ group.there was no change in the brin of SS group and KB group.②The expression of HSP70 in the brain was observed,which in IP group,DZ group and DY group was markedly increased than that in MCAO group.The expression of HSP70 in the brain of DY group was moderate detected.there was no almost expression in the SS group and KB group.③The expression of TNF-αmRNA: The expression of TNF-αwas observed in the four groups.In contrast with MCAO group,the expression of TNF-αmRNA was down-regulated significantly in the DY group and the further down-regulation were observed in the IP group and DZ group.Conclusion①Tanshinone preconditioning can induce endogenous neuroprotectant in organism,and protects against neuronal damage after subsequent lethal ischemic insults.②Up-regulation of the expression of heat shock proteins-70 and down-regulation of tumor necrosis factor-alpha might play important roles in the induction of endogenous neuroprotec -tion.