Effect Of Electroacupuncture On The Immunological Inflammatory Reaction In Frontal Lobe And Hippocampus Of AD Rats

Objective To observe the immunological inflammatory reaction, phosphorylation of P₃₈MAPK,and neuronic ultrastructural change in frontal lobe and hippocampus of Alzheimer's disease(AD) rats,and the effect of electroacupuncture on them.And to explore the possible mechanism of treating AD by electroacupuncture.Methods 103 normal SD rats were selected out from 110 rats with 24 months by the method of Y type water maze.Then from the 103 rats,30 rats were randomly selected into normal group and sham-operation group,with 15 rats in each group.The model of Alzheimer disease was established by stereotaxis injection agglutinated Aβ_1-40 into rat's bilateral Meynert basal nuclei.On the thirty-first day after model preparation,the rats were screened again with the method of Y type water maze.In 15 tests,if the correct times lower 1/3 than that before,the model was the successful model.The model rats were randomly selected into model group and(EA) group,with 16 rats in model group and 17rats in EA group.The points of "Baihui","Taixi" and "Zusanli" were selected to treat the rats in EA group by electroacupuncture. The treatment was once a day and 6 days was a course of treatment.The next time of therapy continued after one day's rest,and the total treatment time was 2 courses.The learning and memory ability was tested in the ethology experiment by Morris water maze,the expression change of microglia,astrocytes,IL-1βand TNF-αof frontal lobe and hippocampus in rats were observed by immunohistochemical method of S ABC,the expression of IL-1βmRNA and TNF-αmRNA were observed by RT-PCR,the phosphorylation of P₃₈MAPK were observed by Western-blot,the neuronic ultrastructural change of frontal lobe and hippocampus in rats were observed by transmission electron microscope.All data were put into the computer and analyzed by SPSS13.0 statistical package.The experiment results were expressed as mean±standard deviation((?) x±s).Results(1) To indicate by the results in the ethology experiment by Morris water maze:In the location see trial,on the first day,the escape latent period in model group and EA group was remarkably longer than that in normal group and sham-operation group(P<0.01);there was no significant difference between model group and EA group,normal group and sham-operation group(P>0.05);on the second day,third day,fourth day and fifth day,the escape latent period in EA group was obviously shorter than model group(P<0.01).And the escape latent period shortened gradually in each group as the swimming days increased,but there were obviously difference between them.In space search test,time percentage and frequency percentage of spanning the platform quadrant remarkably decreased,10% percentage and 30%percentage remarkably increased in the rats of model group,there were significant differences compared with normal group and sham-operation group(P<0.01);time percentage and frequency percentage in EA group remarkably increased,10%percentage and 30%percentage in EA group evidently decreased,there were significant differences compared with model group(P<0.01).(2) The number of positive cells of GFAP and CD68, and the expression of IL-1βand TNF-αin model group obviously increased, their dyeing was deepened,there were significant differences in comparison with normal group and sham-operation group(P<0.01);After the treatment of electroacupuncture,they remarkably decreased,there were significant differences in comparison with model group,P<0.01.(3) To sign in the experiment of RT-PCR:the expression of IL-1βmRNA and TNF-αmRNA in frontal lobe and hippocampus of model group evidently enhanced,there were significant differences in comparison with normal group and sham-operation group(P<0.05-0.01);the expression of IL-βmRNA and TNF-αmRNA in EA group obviously reduced,compareing with model group,P< 0.05-0.01.(4) To show in the experiment of Western-blot:There were expression of p-P₃₈MAPK in frontal lobe and hippocampus of each group,but the expression in model group was maximum,there were significant differences in comparison with normal group and sham-operation group(P< 0.01);After the treatment of electroacupuncture,the expression remarkably decreased,there were significant differences in comparison with model group(P<0.01).(5) in frontal lobe and hippocampus of the rats in model group, we observed some nerve cells degenerated by transmission electron microscope,endoplasmic reticulum of inter organelle expanded and mitochondriom swelled.However,in frontal lobe and hippocampus of rats in EA group,cell nucleus was almost normal and mitochondrion in organelle swelled a little.There weren't above-mentioned changes in the nerve cells of frontal lobe and hippocampus of the rats in normal group and sham-operation group.The cell membrane was integral,electron density in ground substance of cytoplasm was well-distributed,biomembrane was integral and the structure was clear.There weren't obvious pathological changes in the nerve cells of the rats in these two groups.Conclusion The results in present research indicated that agglutinated Aβ_1-40 injected into rat's bilateral Meynert basal nuclei could cause the immunological inflammatory reaction in central nervous system. Electroacupuncture can decrease the number of microglial cells vivid and astrocytes vivid,reduce the expression of IL-1βand TNF-α,IL-1βmRNA and TNF-αmRNA,p-P₃₈MAPK,thereby restrain inflammatory reaction in frontal lobe and hippocampus of AD rats,antagonize toxic action in central nervous system caused by ABBBBBBB_1-40,inhibitory nerve cells to degenerate and necrosis.