Molecular Mechanism Research Of Electroacupuncture At Zusanli On Stress-induced Gastric Mucosal Injury Repair In Rats

Objective:To observe the effect of electroacupuncture at Zusanli on P2X receptors, HSP60, HSP70mRNA of stomach of stress-induced ulcer rats model and explore the molecular mechanism of electroacupuncture at Zusanli preventing and treating gastric ulcer.Methods:51SD rats were randomly divided into three groups, including normal control group(Normal Group), stress-induced gastric ulcer group (Model Group) and electroacupuncture at Zusanli group (EA Group). The rat model of stress-induced ulcer was constructed by cold-restraint method. From the next day after making model, EA Group received EA at Zusanli20minutes for three consecutive days, alternating left and right Zusanli. There was no treatment for Model Group, except for bondage as EA Group done. Normal Group received no administration. We got the stomach to observe Ulcer Index (UI) by Guth method, pathohistology by HE stain and expression of HSP70mRNA by RT-PCR.Results:1. Compared with Normal Group, the UI of Model Group was significantly higher (P<O.001), which proved that the model was made successfully; Compared with Model Group, the UI of EA Group was significantly reduced (P<0.05), which prompted that EA Zusanli promoted ulcer healing.2. Histopathology observation:(1)The naked eye:the gastric mucosal tissue of Normal Group kept intact and no corrosive focus or ulcer was observed. Compared with Normal Group, the mucosas of Model Group and EA group were damaged. Varying amounts and sizes of ulcers were shown in the stomach of Model Group and EA group. Ulcers were more concentrated in the gastric body.(2)Optical microscopy: Normal Group:the structure of the stomach was intact; gastric glands were arrayed evenly; there was no infiltration of the mucosa by inflammatory cell. Model Group:gastric mucosa was broken; the mucosa in the focus of the ulcer was defective or shedding; the glands closed the ulcer lesions were completely destroyed; there was infiltration of the mucosa by inflammatory cell. EA group:gastric mucosa of rats were partial broken; the defective area was smaller than Model Group; the array of the glands closed the ulcer lesions was uneven; there was no obvious infiltration of the mucosa by inflammatory cell; the focus of the ulcers was covered with columnar epithelial cells.3. There were six subtypes of P2X receptors except P2X6in gastric tissue of rats in each group. Correlation analysis for six P2X subtypes of Normal Group showed that there was a significant positive correlation among P2X2, P2X4and P2X7(P<0.01); and significantly positive associated between P2X3and P2X5(P<0.05).Compared with Normal Group, the P2Xi mRNA in the gastric tissue of Model Group was significantly decreased (P<0.01), while the P2X1mRNA of EA group was significantly higher than Model Group (P<0.05), which prompt the mechanism of that EA Zusanli healed stress-induced gastric ulcer may be associated with P2X1receptor. The other subtypes had no significant differences among groups.4.Model Group compared with Normal Group, HSP70mRNA of gastric tissue was significantly decreased (P<0.05); EA group compared with Model group, HSP60mRNA(P <0.05) and HSP70mRNA (P<0.01) of gastric tissue were significantly increased; which suggested that EA Zusanli healed stress-induced gastric ulcer may be associated with HSP60, HSP70mRNA’s upregulation.Conclusion:EA Zusanli could enhance the expression of P2X1, HSP60and HSP70mRNA in the stomach of the stress-induced gastric ulcer rats and repair gastric mucosal damage.