粗齿兔耳风提取物利尿活性及其机制

目的：研究粗齿兔耳风提取物对大鼠的利尿作用并探讨其机制。方法：将大鼠随机分为5组，每组6只，兔耳风提取物高、中、低剂量（2.5，10，20 g·kg^-1）和呋塞米（10 mg·kg^-1）灌胃给药。第1次给药后，收集大鼠1，2，4，6，24 h的尿液，研究并比较各给药组对大鼠排尿量和尿中Na⁺，K⁺，Cl^-排泄量的影响。连续给药8 d，取其肾脏研究各给药组对肾髓质水通道蛋白（AQP）₁，AQP₂，AQP₃的mRNA表达影响。结果：与正常组比较，单次给药后粗齿兔耳风提取物在4 h后能明显增加大鼠的尿液量，24 h尿液中Na⁺，K⁺，Cl^-的浓度明显增加。每天给药1次，给药8 d后与正常组比较，粗齿兔耳风提取物给药组能显著下调大鼠肾髓质水通道蛋白AQP₂的mRNA表达，对AQP₃的mRNA表达也有一定的下调作用，对AQP₁的mRNA表达调节作用则无显著性差异。结论：粗齿兔耳风提取物具有利尿作用，促进Na⁺，K⁺，Cl^-的排泄和抑制水通道蛋白AQP₂，AQP₃mRNA表达是其可能机制。

Diuretic Activity and Mechanism of Ainsliaea grossedentata

Objective: The aim of the present study was to evaluate the diuretic effect and explore its mechanism of Ainsliaea grossedentata in water-loaded rats. Method: The rats were divided and given extractive of A.grossedentata at three different dose(2.5,10,20 g·kg^-1),and given furosemide(10 mg·kg^-1) as positive control group. After the first administration,the urine of rats was collected at 1,2,4,6,24 h to study the effect of urine output and electrolyte concentration (Na⁺, K⁺ and Cl^-) and regulation of the relative mRNA expression of aquaporin-1 (AQP₁), aquaporin-2 (AQP₂) and aquaporin-3 (AQP₃) in water-loaded rats. Result: Compared with normal group, after single dose of the extract of A. grossedentata, urine output was significantly increased, which began at 4 h after the treatment. The extract increased urinary levels of Na⁺, K⁺, and Cl^- at 24 h markedly. After administration of 8 days,the extract significantly reduced expression of AQP₂ and lower expression of AQP₃ to some extent, but there was no significant difference in the expression of AQP₁. Conclusion: A. grossedentata has conspicuous diuretic activity, the possible mechanisms may restrain the relative mRNA expression of AQP₁ and AQP₂ as well as renal tubular reabsorption function.