Experimental Research Of Erk Signaling Pathway By Electric Against Cerebral Ischemia Re-perfusion Rats

Objective:To observe the effect of electro acupuncture on cerebral ischemia re-perfusion rats by extracellular signal regulated kinase (ERK) signal pathway,to explore the mechanism of electro acupuncture against cell apoptosis on cerebral ischemia re-perfusion injury.Methods:250healthy SD male rats were randomly divided into5groups: sham-operation group,model group,electro acupuncture group,ERK blocker group,ERK blocker plus electro acupuncture group,50rats per group.According to different time,Each group were randomly divided into5subgroups,which include2hours,6hours,1day,3days,1week.10rats per subgroup.Except the sham operation group, the rest rats were used to establish the cerebral ischemia re-perfusion(CIR) model by using the improved thread embolism method, electro acupuncture group were given electro acupuncture treatment,ERK blocker group were injected PD98059in the corresponding brain regions, electro acupuncture plus EPK blocker group rats were given electro acupuncture treatment after injected PD98059and finished I/R model, adopt the neurological score to evaluate the overall function of motor behavior; using TTC and HE staining to observe the morphological changes of the brain; adopt TUNEL method for the detection of focal nerve cell apoptosis index;using immunohistochemical detection of p-ERK protein expression level.Results:1.Comparison of neural function defect score:at the same time, the model group, EA group, ERK blocker group, ERK blocker+EA group,all those group of nerve function defect score was significantly higher than that in sham operation group (p<0.01); Electro acupuncture group compared with model group, there was significant difference in third days(p<0.05),1week (p<0.01); ERK blocker+EA group compared with the ERK blocker,the former has neural function defect score slightly lower in the third days,1week.2.Morphological comparison:general shape, compared with the sham operation group, each group had different degree of cerebral infarction (P<0.01), Electro acupuncture group,ERK blocker+EA group have smaller cerebral infarction than in model group, in6hours,1day,3days and1week time point (P<0.05),3days,1week time point had a significant difference (P<0.01); ERK blocker+EA group has light degree infarction compared withe ERK blocker group, in3days,1week time points (P<0.05); On the morphology, compared with the sham operation group, the other groups were found varying degrees of cell destruction, degeneration and necrosis; Electro acupuncture group has a lesser degree of necrosis than model group, ERK blocker group, ERK blocker+EA group.3.Apoptosis:cell shrinkage, cell size, reduced contact between normal, core extensive chromatin condensation, those apoptosis expression and apoptosis index, Sham operation group were significantly lower than those in the model group, EA group, ERK blocker group, ERK blocker group+EA group (P<0.01);EA group apoptosis expression and apoptosis index significantly lower than those in the model group, at1day,3days had significant differences (P<0.01); ERK blocker+EA group had a light apoptosis compared with the ERK blocker group, in the third days (P<0.05).4.Comparison of p-ERK protein levels:The ipsilateral cortex is consistent with p-ERK expression in hippocampus CA1region, sham operation group,blocker group at each time point expression is not obvious,the model group was significantly decreased expression,but the presentation process,1day after the beginning of expression,3days,1week time point and was similar to the sham operation group;compared with the model group,each time point,EA group,ERK blocker+EA group had a up regulate expression of p-ERK,in the third days,1week (P<0.01); ERK blocker+EA group and the ERK blocker group, the former expression was increased,2hours,6hours,1day time points (P<0.01),3days,1week (P<0.05). Conclusion:1.Electro acupuncture with "chize, Hegu","Zusanli, Sanyinjiao"can improve the neural function defect and ischemic brain tissue morphology of the cerebral ischemia re-perfusion model rats. Above prompt that Electro acupuncture with"chize, Hegu","Zusanli, Sanyinjiao" has a protective effect on ischemic brain injury2.Electro acupuncture with "chize, Hegu","Zusanli, Sanyinjiao"can improve apoptosis expression of the cerebral ischemia re-perfusion rats.Above prompt that Electro acupuncture with those acupoint can combat cell apoptosis after cerebral ischemia damage.3.Electro acupuncture with "chize, Hegu","Zusanli, Sanyinjiao"can increase the p-ERK of rats after molding,this suggesting that activation of ERK signal transduction pathway is one of the important characteristics of electro acupuncture with "chize, Hegu","Zusanli, Sanyinjiao"promote ischemic brain damage repair.4. Effect of electro acupuncture with "chize, Hegu","Zusanli, Sanyinjiao"on improvement of neural function defect,brain morphology,cell apoptosis index and up regulation of p-ERK in1day time point is most obvious after cerebral ischemia re-perfusion.It is indicated that the1day time point is the therapeutic tiome window to promote better of self repair. 5.It is shown that the "acupuncture stimulation on ERK signaling regulation-antagonized apoptosis", is the acupuncture treatment of cerebral ischemia/re-perfusion brain injury is one of the key mechanisms of action.