Objective: To observe the effect of electroacupuncture preconditioning at "Zusanli"(ST36，Lower Confluent point) and "Zhongwan"(CV12，Front-Mu point) combination on oxidative stress and inflammation-related indicators, Toll-like receptor 4 (TLR4), myeloid differentiation factor 88 (MyD88) and inhibitor-α of nuclear transcription factor κB (IκB-α) in serum and gastric tissue of rats with stress gastric ulcer(SGU)，so as to explore its mechanisms underlying prevention of SGU.
Methods: A total of 36 Wistar rats were randomly divided into blank control, model, positive drug and He-Sea-Front-Mu point combination groups (n=9 in each group). A rat model of SGU was established by restraint water-immersion stress method. Ten days before mode-ling, rats in the He-Sea-Front-Mu point combination group received electroacupuncture （2 Hz, 0.6 mA）at ST36 and CV12 for 10 min once every other day for 10 days, and those in the positive drug group was treated by gavage of omeprazole (20 mg/kg) once every other day for 10 days. The morphology of the gastric mucosa was observed by naked eyes and hematoxylin-eosin staining, and the ulcer index (UI) and lesion score were calculated. TBA and colorimetric methods, ELISA and Western blot were used to detect malondialdehyde (MDA), myeloperoxidase (MPO), glutathione peroxidase (GSH-Px), tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6) levels and the relative expressions of TLR4, MyD88, and IκB-α protein, separately.
Results: The gastric mucosa of rats in the blank control group was smooth and intact, the cells were arranged neatly, and there was no telangiec-tasia, hyperemia and inflammatory cell infiltration. The gastric mucosal epithelial structure of rats in the model group was destroyed, and a large number of mucosal epithelial cell death and inflammatory cell infiltration were seen. The degree of gastric mucosal injury and inflammatory cell infiltration in the positive drug group and the combined point group was less than that in the model group. Compared with the blank control group, the UI and lesion score of rats in the model group were significantly increased (P<0.05), the levels of MDA and MPO in the serum and gastric tissues were significantly increased (P<0.05), GSH-Px was significantly reduced (P<0.05), the contents of TNF-α and IL-6 in serum were markedly increased (P<0.05), the expression levels of TLR4 and MyD88 proteins in gastric tissue were significantly increased (P<0.05), IκB-α was significantly reduced (P<0.05). After intervention and in comparison with the model group showed that, the UI and lesion score, the levels of MDA and MPO, contents of serum TNF-α and IL-6, expression levels of TLR4 and MyD88 proteins in positive drug and He-Sea-Front-Mu point combination groups were significantly decreased (P<0.05), while GSH-Px and IκB-α were significantly increased (P<0.05); There were no significant differences in the above indicators between the positive drug and the He-Sea-Front -Mu point combination groups （except TNF-α）.
Conclusion: Electroacupuncture preconditioning at ST36 and CV12 can prevent SGU, which may be related to its effects in anti-oxidant, anti-inflammatory and regulating TLR4/MyD88/IκB signaling pathway.
目的：观察合募配穴对应激性胃溃疡(SGU)大鼠血清及胃组织氧化应激及炎性反应相关指标Toll样受体4(TLR4)、髓样分化因子88(MyD88)、核转录因子κB抑制蛋白α(IκB-α)的影响，探讨合募配穴预防SGU的机制。方法：Wistar大鼠随机分为空白组、模型组、阳性药组和合募配穴组，每组9只。采用束缚-水浸应激法建立SGU大鼠模型。造模前10 d，合募配穴组予以电针“中脘”“足三里”（2 Hz,0.6 mA），10 min/次，阳性药组予以奥美拉唑溶液(20 mg/kg)灌胃，两组均隔日干预1次，共10 d。肉眼及苏木精-伊红染色法观察各组大鼠胃黏膜的形态、计算溃疡指数(UI)和病变积分；TBA法和比色法检测各组大鼠血清和胃组织中丙二醛(MDA)、髓过氧化物酶(MPO)、谷胱甘肽过氧化物酶(GSH-Px)的水平；ELISA法检测各组大鼠血清肿瘤坏死因子α(TNF-α)、白细胞介素6(IL-6)含量；Western blot法检测胃组织中TLR4、MyD88、IκB-α蛋白的相对表达量。结果：空白组大鼠胃黏膜层光滑完整，细胞排列整齐，未见毛细血管扩张充血和炎性细胞浸润。模型组大鼠胃黏膜上皮结构破坏，可见大量黏膜上皮细胞死亡及炎性细胞浸润。阳性药组和合募配穴组胃黏膜损伤和炎细胞浸润程度较模型组轻。与空白组比较，模型组大鼠的UI及胃黏膜病变积分显著升高(P<0.05)，血清和胃组织中MDA含量、MPO活性显著升高(P<0.05)，GSH-Px活性显著降低(P<0.05)，血清中TNF-α、IL-6含量显著增加(P<0.05)，胃组织中TLR4、MyD88蛋白表达水平显著升高(P<0.05)、IκB-α表达水平显著降低(P<0.05)；与模型组比较，阳性药组与合募配穴组的UI及胃黏膜病变积分显著降低(P<0.05)，血清和胃组织中MPO活性显著降低(P<0.05)、GSH-Px活性显著升高(P<0.05)，血清中TNF-α、IL-6含量显著降低(P<0.05)，胃组织中MDA含量和TLR4、MyD88蛋白表达水平显著减少(P<0.05)、IκB-α表达水平显著增加(P<0.05)；合募配穴组血清TNF-α的含量低于阳性药组（P<0.05）。结论：合募配穴预电针可保护SGU大鼠的胃黏膜组织，其机制可能与抗氧化、抗炎和调节TLR4/MyD88/IκB信号通路有关。.
Keywords: Electroacupuncture; Inflammation; Oxidative stress; Stress gastric ulcer.