Effects of electroacupuncture on expression of PKC mRNA, mGluRs and AMPAR in hippocampus of rats with vascular dementia

Abstract

Objective To observe the effect of electroacupuncture on the hippocampal PKC mRNA,mGluRs and AMPAR expression in rats with vascular dementia (VD),so as to explore the underlying mechanisms of electroacupuncture (EA) therapy for VD.Methods Thirty Sprague-Dawley rats were randomly divided into a sham-operation group,a model group and an EA group(10 in each group).VD model was established by repeated ischemia/reperfusion.Then the rats were placed in the rat fixer with their heads and back exposed.The electro-acupuncture were superficially inserted into “ Baihui” (GV20) and “ Dazhui” (DU14) in rats.EA was applied to “Baihui” (GV20),“Dazhui” (DU14) in EA group for 20 min,once daily for 10 days.The PKC mRNA,mGluRs and AMPAR expression in hippocampal tissue were examined by RT-PCR and immunohistochemical assay.Results The expression level of PKC mRNA in hippocampus of the model group was lower than that of the shamoperation group.Compared with the model group,the level of PKC mRNA was significantly increased in the EA group (P ＜ 0.05).The mGluRs immunoreactive cell integrated optical density (IOD) in hippocampus in the sham-operation group,the model group and the EA group were (58.6 ±3.6),(36.3 ±2.5) and (51.5 ±4.8),respectively; the mGluRs immunoreactive cell IOD in hippocampus in the model group was reduced significantly (P ＜0.01) when compared with the sham-operation group,The mGluRs immunoreactive cell IOD in hippocampus in the EA group was increased significantly as compared with the model group (P ＜ 0.05).AMPAR immunoreactive cell IOD in hippocampus in the sham-operation,the model group and the EA group were (66.5 ± 2.8),(40.1 ± 5.1) and (58.3 ± 4.6),respectively,and compared with the sham-operation group,the AMPAR immunoreactive cell IOD in hippocampus in the model group was reduced significantly.The difference of the AMPAR immunoreactive cell IOD in hippocampus between the sham-operation group and the model group were statistically significant (P ＜0.01) ; and compared with the model group,the AMPAR immunoreactive cell IOD in hippocampus in the EA group was increased significantly.The difference of the AMPAR immunoreactive cell IOD in hippocampus between the model group and EA group was statistically significant (P ＜0.05).Conclusion EA can enhance the expression of PKC mRNA,mGluRs and AMPAR.These results may contribute to the therapeutic effects of electroacupuncture on VD rats. Key words: Vascular dementia; Electroacupuncture; PKC mRNA; mGluRs; AMPAR