Disruption of glial function regulates the effects of electro-acupuncture at Tsusanli on gastric activity in rats

According to recent evidence, acupuncture at Tsusanli (ST 36) can regulate gastric activity. And this regulation mainly depends upon neural basis or structure and may probably relate to the central neurons in the dorsal vagal complex. However, whether the glias of the dorsal vagal complex participate in the regulation of gastric activity, when electro-acupuncture (EA) at Tsusanli, still remains to be interpreted. In this study, we observed the effect of EA at Tsusanli (ST 36) on regulation of gastric activity. Propentofylline (PPF), a glial metabolic inhibitor, was used to inhibit the function of glial cells. EA at Tsusanli showed that the expressions of glial fibrillary acidic protein (GFAP) and OX42 increased significantly compared to that of the control group, and gastric electric change was obvious, with significantly higher frequency and wave amplitude compared to the control group. The expressions of GFAP and OX42 were decreased markedly when pretreated with PPF group than without PPF pretreatment group. Compared to the Tsusanli group and the control group, the changes of electro gastric graph (EGG) were significantly decreased in PPF pretreatment group. On the other hand, we observed the changes of spontaneous electro-activity of the DVC (dorsal vagal complex) in our previous experiment. The results indicated that EA at Tsusanli could activate glial cells in the dorsal vagal complex and regulate gastric activity. PPF blocked the function of glia, thus the effect of EA at Tsusanli on gastric activity was weakened. Our study suggested that this electro-acupuncture regulation of gastric activity was possibly related with glia of the dorsal vagal complex.