基于水通道蛋白的知母利水功效研究

目的 通过建立水负荷模型，观察不同剂量知母水提物对大鼠尿量及水通道蛋白（AQP）相关指标的影响，探究其利水功效。方法 将实验动物分为对照组、模型组和知母水提物高、中、低剂量（4.56、3.04、1.52 mg/kg）组，置于代谢笼中，每天9：00时ig给药，对照组和模型组给予等体积蒸馏水，连续3 d，记录每日饮水量、日间8 h尿量、夜间12 h尿量。第4天除对照组外其余各组大鼠ip生理盐水5 mL，同时ig生理盐水5 mL，连续收集6 h尿量，分别记录0~2、2~4、4~6 h尿量。水负荷实验结束后，取各组大鼠的气管、肝脏、肾脏、大肠、小肠、胰腺、心脏、肺脏、唾腺。酶联免疫法检测气管中AQP3、AQP4，肝脏中AQP9，肾脏中AQP2，小肠中AQP4，大肠中AQP2，胰腺中AQP3，心脏中AQP1，肺脏中AQP3、AQP4，唾腺中AQP5蛋白表达。结果 高剂量知母水提物的利水作用起效较慢，与对照组比较，正常大鼠第2、3天夜间12 h尿量显著增加（P<0.05、0.01）；与模型组比较，高剂量组水负荷大鼠2~4、4~6 h尿量及总尿量均显著增加（P<0.05），气管AQP4、肝脏AQP9、肾脏AQP2、胰腺AQP3、心脏AQP1蛋白表达均显著下降（P<0.05、0.01）；中剂量利水作用起效较快，与对照组比较，正常大鼠第1天日间8 h尿量、夜间12 h尿量显著增加（P<0.05、0.01）；与模型组比较，中剂量组水负荷大鼠0~2、2~4 h尿量及总尿量均显著增加（P<0.05），小肠AQP4，肺脏、气管AQP3，心脏AQP1蛋白含量显著降低（P<0.05、0.01）；与模型组比较，知母水提物低剂量组的水负荷大鼠肺、小肠AQP4，大肠、气管AQP3和肝脏AQP9的蛋白表达显著降低（P<0.05、0.01）。结论 知母水提物通过抑制AQP的表达，抑制机体对水的重吸收，起到利水作用。

Study on water effect of Anemarrhena asphodeloides by aquaporin

Objective To observe the effects of different doses of Anemarrhena asphodeloides Bge. on urine volume and the targets of aquaporin, by establishing a rat model of water load. Methods Animals were divided into five group, which are control group, model group, high, middle, and low dose (4.56, 3.04 and 1.52 mg/kg) of aqueous extract from Anemarrhena asphodeloides (AEAA) group, drugs were ig at 9 o''clock daily, rats in control and the model group were gave distilled water at same volume, which would last three days. The daily water intake, the urine volume of 8 h in the daytime and the urine volume of 12 h at night should be reworded. On the fourth day, except the control group, rats in the other groups were ip given with saline 5 mL and ig saline 5 mL. The urine volume was continuously collected for 6 hours, and the urine volume was recorded for 0~2, 2~4 and 4~6 hours respectively. At the end of the water load experiment, the trachea, liver, kidney, large intestine, small intestine, pancreas, heart, lung and salivary glands of rats in each group were taken. It indicated tube ELISA AQP3 and AQP4, AQP9 in liver, AQP2 in kidney, small intestine AQP4, AQP2, AQP3 AQP1 in the pancreas, heart, lung AQP3, AQP4, AQP5 in salivary gland. Results The high dose of AEAA had the slower response. Compared with control group, the nocturnal 12-hour urine volume of normal rats increased significantly on the 2nd and 3rd day (P<0.05, 0.01); compared with the model group, the urine volume and total urine volume of water-loaded rats increased significantly (P<0.05), while the expression of AQP4 in trachea, AQP9 in liver, AQP2 in kidney, AQP3 in pancreas and AQP1 in heart decreased significantly (P<0.05, 0.01). The diuretic effect of medium dose was more effective. Compared with control group, the daily urine volume of 8 hours and the nocturnal urine volume of normal rats increased significantly on the first day (P<0.05, 0.01); compared with the model group, the urine volume and total urine volume of 0~2 h, 2~4 h in the middle dose group increased significantly (P<0.05), the small intestine AQP4, lung and trachea AQP3, and the cardiac AQP1 protein content decreased significantly (P<0.05, 0.01). Compared with model group, the expression of AQP4 in lung and small intestine, AQP3 in large intestine, trachea and AQP9 in liver were significantly decreased in low dose group (P<0.05, 0.01). Conclusion AEAA plays a water-diversifying role by inhibiting the expression of AQP and restraining the body''s re-absorption of water.