一贯煎对慢性萎缩性胃炎癌前病变大鼠甲状腺功能和TGF-β_(1)/Smad通路的影响

Effect of Yiguanjian Decoction on thyroid function and TGF-β_(1)/Smad pathway in rats with precancerous lesion of chronic atrophic gastritis

目的观察一贯煎对慢性萎缩性胃炎(CAG)癌前病变大鼠甲状腺激素和转化生长因子-β_(1)(TGF-β_(1))/Smad信号通路的调节作用。方法将60只Wistar大鼠随机分为空白组、模型组、维酶素组、一贯煎低剂量组、一贯煎中剂量组和一贯煎高剂量组,每组10只。除空白组大鼠正常饲养外,其余各组大鼠均采用甲基硝基亚硝基胍自由饮用+乙醇灌胃+饥饱失常的综合方法复制CAG癌前病变模型。造模成功后,维酶素组给予维酶素0.3 g/kg灌胃,一贯煎低、中、高剂量组分别给予一贯煎液4.84,9.68,19.35 g/kg灌胃,空白组和模型组给予等量生理盐水灌胃,均每日1次,持续灌胃12周。采用中性红清除法检测各组大鼠胃黏膜血流量,HE染色观察胃黏膜病理形态,免疫组化法检测胃黏膜组织中Ki67的阳性表达情况,ELISA法检测血清中三碘甲状腺原氨酸(T3)、甲状腺素(T4)及促甲状腺素(TSH)水平,Western blot法及RT-PCR法检测胃黏膜组织中TGF-β_(1)、Smad3、Smad4的蛋白和mRNA表达情况。结果与空白组比较,模型组大鼠胃黏膜血流量明显减少(P<0.05);胃黏膜萎缩,可见炎性细胞浸润和异型增生;胃黏膜组织中Ki67的阳性表达明显增多(P<0.05);血清T3、T4、TSH水平均明显降低(P均<0.05);胃黏膜组织中TGF-β_(1)蛋白和mRNA相对表达量均明显升高(P均<0.05),Smad3、Smad4蛋白和mRNA相对表达量均明显降低(P均<0.05)。与模型组比较,维酶素组和一贯煎各剂量组大鼠胃黏膜血流量均明显增加(P均<0.05);胃黏膜萎缩和异型增生情况改善;胃黏膜组织中Ki67阳性表达明显减少(P均<0.05);血清T3、T4、TSH水平均明显增高(P均<0.05);黏膜组织中TGF-β_(1)蛋白和mRNA相对表达量均明显降低(P均<0.05),Smad3、Smad4蛋白和mRNA相对表达量均明显升高(P均<0.05)。结论一贯煎能明显增加CAG癌前病变大鼠胃黏膜血流量,改善胃黏膜病变,调节大鼠甲状腺功能,其机制可能与抑制TGF-β_(1)/Smad通路的激活相关。

Objective It is to observe the regulating effect of Yiguanjian Decoction on thyroid hormone and transforming growth factor-β_(1)(TFG-β_(1))/Smad signaling pathway in rats with precancerous lesions of chronic atrophic gastritis(CAG).Methods Sixty Wistar rats were randomly divided into 6 groups:blank group,model group,vitacoenzyme group,Yiguanjian Decoction low-dose group,middle-dose group and high-dose group,with 10 rats in each group.Except for the rats in the blank group fed normally,the rats in the other groups were used to replicate the models of CAG precancerous lesion by the comprehensive method of free drinking of methyl nitrosonitrosoguanidine(MNNG)+ethanol gavage+hunger-satiety.After the models were successfully established,the vitacoenzyme group was given vitacoenzyme 0.3 g/kg by gavage,and the low,medium,and high dose groups of Yiguanjian Decoction were respectively given Yiguanjian Decoction 4.84,9.68,19.35 g/kg by gavage,the blank group and model group were given the same volume of normal saline by gavage,all once a day,continuously treated for 12 weeks.The gastric mucosal blood flow of rats in each group was detected by neutral red clearance,the morphological changes of gastric mucosa were observed by HE staining,the positive expression of Ki67 was detected by immunohistochemistry,and the levels of serum triiodothyronine(T3),thyroxine(T4)and thyrotropin(TSH)were detected by ELISA,the protein and mRNA expression of TGF-β_(1),Smad3 and Smad4 in gastric mucosa tissue were detected by Western-Blot and RT-PCR.Results Compared with the blank group,the gastric mucosal blood flow of rats in the model group was significantly decreased(P<0.05),the gastric mucosa was atrophy with inflammatory cell infiltration and intestinal metaplasia and dysplasia,the positive expression of Ki67 in gastric mucosa was increased significantly,and the levels of serum T3,T4 and TSH were significantly reduced(all P<0.05),TGF-β_(1)protein and mRNA relative expression in gastric mucosal tissues were significantly increased,those of Smad3 and Smad4 were significantly decreased(all P<0.05).Compared with the model group,the gastric mucosal blood flow of rats in the vitacoenzyme group,low,medium and high dose groups of Yiguanjian Decoction were significantly increased(all P<0.05),and the gastric mucosal atrophy and intestinal metaplasia were improved,the positive expression of Ki67 in gastric mucosa was significantly decreased(P<0.05),the levels of serum T3,T4,TSH were significantly increased(all P<0.05),TGF-β_(1)protein and mRNA relative expression in gastric mucosal tissues were significantly decreased(all P<0.05),those of Smad3 and Smad4 were significantly increased(all P<0.05).Conclusion Yiguanjian Decoction can significantly increase gastric mucosal blood flow,improve gastric mucosal lesions,regulate thyroid function in rats with precancerous lesions of chronic atrophic gastritis,and the mechanism may be related to inhibiting the activation of TGF-β_(1)/Smad pathway.