艾灸对脾虚胃溃疡模型大鼠胃组织表皮生长因子受体、磷酸化细胞外信号调节激酶的影响

目的:观察艾灸对脾虚胃溃疡模型大鼠胃组织表皮生长因子受体(EGFR)和磷酸化细胞外信号调节激酶(p-ERK1/2)蛋白表达的影响,初步探讨其作用机制。方法:SD大鼠随机分为空白组、模型组、四君子汤组、艾灸非穴位组和艾灸组,每组10只。采用大黄浓缩液灌胃法建立大鼠脾虚模型,在此基础上运用无水乙醇灌胃法制备脾虚胃溃疡大鼠模型。四君子汤组予以四君子汤灌胃,艾灸组大鼠隔日交替灸"足三里""中脘"或"脾俞""胃俞",艾灸非穴位组灸艾灸组穴位的对照点,每日1次,共治疗8d。按脾虚动物模型标准观察大鼠脾虚症状,按Guth法计算胃黏膜损伤指数,光镜下观察胃黏膜组织形态学变化,免疫组织化学法检测胃组织EGFR的表达和蛋白质印迹法检测p-ERK1/2蛋白的水平。结果:与空白组比较,其余各组造模大鼠脾虚症状明显,模型组大鼠胃黏膜损伤指数显著增加(P0.01),光镜下胃黏膜损伤严重,胃组织EGFR、p-ERK1/2蛋白表达升高(P0.01,P0.05);与模型组比较,四君子汤组、艾灸非穴位组和艾灸组胃黏膜损伤指数显著降低(P0.01,P0.05),光镜下胃黏膜损伤改善,且胃组织EGFR和p-ERK1/2蛋白表达显著升高(P0.01);与艾灸非穴位组相比,四君子汤组和艾灸组胃黏膜损伤指数呈降低趋势,但差异无统计学意义(P0.05),而光镜下胃黏膜损伤恢复较艾灸非穴位组好,胃组织EGFR和p-ERK1/2蛋白表达显著升高(P0.01,P0.05)。结论:激活EGFR/ERK信号转导通路是艾灸启动机体的内源性保护机制之一,艾灸治疗脾虚胃溃疡可能是通过提高胃组织表皮生长因子、转化生长因子的表达,两者均结合并激活EGFR,激活后的EGFR介导ERK磷酸化从而激活EGFR/ERK信号转导通路,因而起到保护胃黏膜、促进胃黏膜增殖修复的作用。

Effect of Moxibustion Intervention on Expression of Gastric Epidermal Growth Factor Receptor and Extracellular Signal Regulated Kinase 1/2 Expression in Rats with Gastric Ulcer

Objective To observe the effect of moxibustion on epidermal growth factor receptor(EGFR)and phosphorylated extracellular signal regulated kinase 1/2(p-ERK1/2)protein expression in gastric ulcer(GU)rats so as to reveal its mechanisms underlying improving GU.Methods Fifty SD rats were randomly allocated to control,model,medication("Sijunzi"Decoction),non-acupoint moxibustion(non-acup-moxi),and acup-moxi groups(n=10in each group).The GU model was established by intragastric perfusion of absolute alcohol.Rats of the control group were treated by gavage of distilled water.Rats of the medication group were treated by administration of"Sijunzi"Decoction(8mL·kg-1·d-1),twice a day for 8days.Moxibustion intervention was applied to bilateral"Zusanli"(ST 36),"Zhongwan"(CV 12),and"Pishu"(BL 20),"Weishu"(BL 21)alternatively for 30 min,once daily for 8days.The animals' ulcer index(UI)was assessed by Guth's method,and gastric mucosal pathological changes were observed under light microscope following H.E.staining.The expression of gastric EGFR was detected by immunohistochemistry and that of phosphorylated ERK1/2(p-ERK1/2)protein determined by Western blot.Results Compared with the control group,the UI,gastric EGFR and p-ERK1/2protein expression levels were significantly increased in the model group(P<0.01,P<0.05);whereas in comparison with the model group,the UI was notably decreased in the medication,non-acup-moxi and acup-moxi groups(P<0.05,P<0.01),and EGFR and p-ERK1/2protein expression levels were further up-regulated in the three treatment groups(P<0.01).The effects of both medication and acup-moxi groups were obviously superior to those of the non-acup-moxi group(P<0.01,P<0.05).No significant differences were found between the medication and acup-moxi groups in the expression levels of EGFR and p-ERK1/2proteins(P>0.05).Results of H.E.staining showed that alcohol-induced gastric mucosal injury as breakage,exfoliation,inflammatory cell infiltration,etc.was milder in both medication and acup-moxi groups following the treatment.Conclusion Acupoint-moxibustion has a role in relieving alcohol induced gastric mucosal injury in the rat,which may be closely associated with its effects in up-regulating activities of the EGFR/ERK signal transduction pathway.