中文摘要：

目的：观察商陆皂苷甲对水负荷大鼠肾脏水通道蛋白2（AQP2）及水通道蛋白4（AQP4）表达的调节作用,研究商陆皂苷甲利尿作用机制。方法：将50只雄性SD大鼠随机分为空白对照组、氢氯噻嗪组及商陆皂苷甲高、中、低剂量组,腹腔注射给药,氢氯噻嗪组给予氢氯噻嗪0.4 mg/kg,商陆皂苷甲高、中、低剂量组分别给5.2、2.6、1.3 mg/kg商陆皂苷甲,收集并测量给药后6 h内的尿量;水负荷实验结束后将大鼠麻醉处死,运用免疫组化及Real Time-PCR技术检测大鼠肾脏AQP2、AQP4蛋白及mRNA表达的变化。结果：与空白对照组比较,商陆皂苷甲高剂量组大鼠尿量显著增多,肾脏AQP2、AQP4蛋白及mRNA的表达显著下调（P〈0.05）;商陆皂苷甲中、低剂量组尿量及肾脏AQP2、AQP4蛋白及mRNA表达差异无统计学意义。结论：商陆皂苷甲通过下调大鼠肾脏AQP2、AQP4蛋白及mRNA表达,使水分重吸收降低,可能是其利尿作用的机制之一。

英文摘要：

Objective ：To observe the regulatory effect of Esculentoside A （EsA）on urination and the expression of AQP＇2 and AQP4 protein of kidney in water-loaded rats ,and to discuss its mechanism of diuresis. Methods ：50 male SD rats were randomly divided into five groups, including blank control group, hydrochlorothiazide group（0. 4 mg/kg）and EsA high, middle and low dose groups（5.2, 2. 6 and 1.3 mg/kg,respectively）. After intraperitoneally injecting of different concentrations of EsA, urinary amount of model rats in continuous six hours was measured. Then the expression of AQP2 and AQP4 protein and mRNA of kidney were detected by immunohis- tochemistry method and Real-Time quantitative PCR. Results ： Compared with blank control group, the expression of AQP2 and AQP4 protein and mRNA of kidney were significantly reduced as well as the urinary amount was significantly increased in EsA high dose group （P 〈 0. 05 ） ,while the expression of AQP2, AQP4 protein and mRNA of kidney as well as urinary amount had no obvious difference in EsA middle and low dose groups. Conclusion：5.2 mg/kg of EsA can reduce the expression of AQP2 and AQP4 protein and mRNA of kidney and the reabsorption of water, which results in diuresis.