车前子对腹泻大鼠小肠黏膜AQP1表达的影响

Effect of Cheqianzi on AQP1 Expression in Small Intestinal Mucosa of Diarrhea Rats

目的:研究车前子对腹泻大鼠小肠组织中水通道蛋白1(AQP1)基因和蛋白表达的影响,探讨其治疗腹泻的作用机制。方法:采用番泻叶灌胃复制大鼠腹泻模型。将60只SD雄性大鼠随机分为正常对照组、模型对照组、阳性药(氢氯噻嗪)对照组和车前子低、中、高剂量组。除正常组外,其余各组均于每日上午灌胃番泻叶水煎液,正常组灌胃等量的蒸馏水;每日下午各治疗组灌服相应的治疗药物,正常组和模型组灌服等量的蒸馏水,给药期间观察大鼠的排便情况,给药2周。麻醉状态下,剖取2份小肠组织,1份置于4%多聚甲醛液中固定,苏木精-伊红(HE)染色法观察小肠黏膜病理形态学变化,1份置于冻存管,液氮冻存,用于qRT-PCR法和Western blot法检测小肠组织AQP1基因和蛋白的表达水平。结果:模型组大鼠排水样稀便;小肠绒毛表皮细胞明显凋亡与坏死,固有层毛细血管扩张充血明显,间质有少量中性粒细胞浸润;小肠组织AQP1基因和蛋白的表达水平均明显低于正常组(P<0.01)。与模型组比较,车前子各剂量组大鼠粪便基本成形;小肠绒毛表皮细胞凋亡、坏死和毛细血管扩张充血现象均减轻,间质有少量中性粒细胞浸润,中、高剂量组可见上皮细胞增生;车前子各剂量组小肠组织AQP1的基因和蛋白的表达水平显著高于模型组(P<0.05或P<0.01),高剂量组高于阳性药组(P<0.05)。结论:车前子具有止泻作用,其机制与上调AQP1的表达水平,增加小肠对水的吸收量、促进水液代谢有关。

Objective:To study the effect of cheqianzi(Plantaginis Semen)on aquaporin-1(AQP1)gene and protein expression in the small intestine of diarrhea rats,and to explore the mechanism of its treatment of diarrhea.Methods:The diarrhea model of rats was induced by intragastric administration with senna leaf.Sixty male SD rats were randomly divided into normal control group,model control group,positive(hydrochlorothiazide)control group and cheqianzi low,medium and high dose group.The normal group were given distilled water of the same amount while the other groups were given senna leaf decoction every morning;each treatment group was given corresponding medicine in the afternoon,while the normal group and the model group were given equal amount of distilled water;the defecation of rats was observed during the administration period,and the administration lasted for 2 weeks.Under anesthesia,two small intestinal tissues were dissected;one was fixed in 4%paraformaldehyde solution to observe the pathological changes of small intestinal mucosa by hematoxylin eosin(HE)staining,and the other was stored in liquid nitrogen for detection of AQP1 gene and protein expression in the small intestine by QRT PCR and Western blot.Results:In the model group,there were watery stools,apoptotic and necrotic epithelial cells in the villi of the small intestine,dilated and congested capillaries in the lamina propria,and infiltration of neutrophils in the stroma,and the expression level of AQP1 gene and protein was significantly lower than that in the normal group(P<0.01).Compared with the model group,the faeces of rats in each dose group of cheqianzi were basically formed;the apoptosis,necrosis and capillary expansion and congestion of small intestinal villi and epidermis cells were alleviated,a small amount of neutrophil infiltration was found in the stroma,epithelial cell proliferation was found in the medium and high dose groups;the expression level of AQP1 gene and protein in each dose group of plantain was significantly higher than that in the model group(P<0.05 or P<0.01),and the high dose group was higher than the positive group(P<0.05).Conclusion:cheqianzi has antidiarrheal effect.Its mechanism is related to up regulating the expression of AQP1,increasing the absorption of water by small intestine and promoting the metabolism of body fluid.