薏苡仁多糖不同组分对脾虚水湿不化模型大鼠结肠VIPR1和AQP3表达的影响

Effect of Different Components of Coix Seed Polysaccharides on the VIPR1 and AQP3 Expression in the Colon of Rats with TCM Syndrome of Dampness Stagnancy Due to Spleen Deficiency

目的:研究薏苡仁多糖不同组分对脾虚水湿不化模型大鼠结肠血管活性肠肽受体1(VIPR1)和水通道蛋白3(AQP3)表达的影响,探讨薏苡仁多糖对脾虚水湿不化模型大鼠水液代谢调控的作用机制。方法:复制脾虚水湿不化大鼠模型,用薏苡仁多糖、薏苡仁多糖组分I、薏苡仁多糖组分II干预后,采用Real time-PCR法检测VIPR1、AQP3的mRNA表达水平变化;Western Blot法检测VIPR1、p-CREB、AQP3蛋白表达水平变化。结果:与对照组比较,模型组结肠VIPR1的mRNA和蛋白表达水平显著升高,而结肠AQP3的mRNA和蛋白表达水平显著降低,p-CREB蛋白表达水平显著降低。与模型组比较,0.9113g/kg的薏苡仁多糖不同拆分组分使结肠组织VIPR1的mRNA和蛋白表达水平均有不同程度的降低,而结肠组织AQP3的mRNA和蛋白表达水平以及p-CREB蛋白表达水平有不同程度的升高,薏苡仁多糖组分I组作用最明显。结论:通过下调结肠中VIPR1的表达及上调AQP3的表达,调控结肠水液代谢可能是薏苡仁多糖治疗脾虚水湿不化模型大鼠的作用机制之一。

Objective： To explore mechanisms of regulation on water metabolism underlying therapeutic effects of different components of coix seed polysaccharides by investigating expressions of vasoactive intestinal peptide receptor 1（ VIPR1） and aquaporin 3（ AQP3） in the colon of the rats with TCM syndrome of dampness stagnancy due to spleen deficiency. Methods： The rat with TCM syndrome of dampness stagnancy due to spleen deficiency was induced by high fat and low protein diet plus swimming exhaustion method. Expressions of VIPR1 mRNA and AQP3 mRNA in the colon were detected by RT-PCR,and expressions of VIPR1,p-CREB and AQP3 in the colon were detected by Western Blot to evaluate the effect of coix seed polysaccharides and components. Results： Compared with the control group,mRNA and protein expression levels of VIPR1 in the colon were significantly increased（ both P 〈 0. 01）,while mRNA and protein expression levels of AQP3 in the colon were remarkably decreased（ both P 〈 0. 01） and the protein expression level of p-CREB in the colon was remarkably decreased（ P 〈 0. 01）in model rats with dampness stagnancy due to spleen deficiency. Different components of coix seed polysaccharides with 0. 9113 g/kg remarkably decreased mRNA and protein expressions of VIP,but significantly increased both mRNA and protein expressions of AQP3 and protein expression of p-CREB,and the effect of coix seed polysaccharide-I was obvious. Conclusion： Coix seed polysaccharides and components could improve the water metabolism of rats with TCM syndrome of dampness stagnancy due to spleen deficiency possibly by down-regulating VIPR1 expression and up-regulating AQP3 expression in the colon.