Effects Of Electroacupuncture On Pain Threshold And Gene Expression Of Enkephalin And β-endorphin In The Hypothalamus

To explore the effects of electroacupuncture with different frequencies and different acupoint combinations on pain threshold of rats and to detect the gene expression of analgesic substances enkephalin and β-endorphin in hypothalamus,which provide reference for electroacupuncture analgesia research.100 Wistars rats were divided into 10 groups as the control group and the frequency of electroacupuncture is 2Hz,50Hz and 100Hz.Each frequency include Houhui with Weigen acupoint group,Houhui with Bashan acupoint group and Houhui with Weigen acupoint group.Comparison the pain threshold changes before and after the electroacupuncture.According to the pain threshold rate,select the control group,Houhui with Weigen acupoint group which electroacupuncture frequency is 2 Hz and Houhui with Bashan acupoint group which electroacupuncture frequency is 50 Hz,the rats were killed after electroacupuncture which hypothalamus was taken out for experiment,the expression of enkephalin and β-endorphin mRNA in hypothalamus was subjected to RT-qPCR and protein expression for immunohistochemistry.The results show that:1.The difference of the frequency of the electroacupuncture for pain threshold was significantly different(P<0.01),but the difference acupoint combinations for the pain threshold was not significant(P>0.05).The pain threshold of the electroacupuncture group increased in some different degrees,there was significant difference between the electroacupuncture groups and the control group(P<0.05),Houhui with Weigen acupoint group which electroacupuncture frequency is 2 Hz had a significant difference compared with the Houhui with Bashan acupoint group which electroacupuncture frequency is 50 Hz,and the other electroacupuncture groups were no significant difference compared each group(P>0.05).2.In the hypothalamus,there was no significant difference in the expression of enkephalin gene in each group,and there was no significant difference in the expression of β-endorphin gene.3.There is a large amount of enkephalin expression in the hypothalamus,and there was no difference in the expression of nuclear variety of hypothalamic analgesic substances.Conclusion:1.Electroacupuncture can improve the pain threshold of animal body and the effect of frequency of 2Hz is better than the frequency of 50Hz and 100Hz.The difference of electroacupuncture effect between the acupoint groups is not obvious.2.Electroacupuncture did not improve the expression of analgesic substances enkephalin and β-endorphin gene in the hypothalamus,indicating that analgesia is the result of interaction between different nuclei in brain tissue.