利尿剂对大鼠肾脏水通道蛋白-2基因表达和尿液水通道蛋白2的影响

Effects of furosemide, antisterone and hydrochlorothiazide on expression of kidney aquaporin-2 gene and urine aquaporin-2 excretion in rats

目的探讨临床常用利尿剂呋塞米、双氢克尿噻及安体舒通对正常大鼠肾脏水通道蛋白-2(AQP2)基因表达及尿液水通道蛋白-2浓度的影响。方法40只健康SD大鼠随机分成4组:对照组、呋塞米组、安体舒通组、双氢克尿噻组。观测尿量、血钠及尿渗量,应用RT-PCR半定量检测肾内髓质AQP2和血管加压素-2型受体(V2-R) mRNA水平,Western blotting检测肾髓质AQP2蛋白含量,酶联免疫吸附测定法(ELISA法)检测尿液AQP2浓度。结果①与对照组比较,利尿剂组大鼠尿量均显著增多(P<0.05),尿液中AQP2浓度明显增加(P<0.05)。但呋塞米组尿渗量低于对照组(P<0.05),而双氢克尿噻组和安体舒通组尿渗量高于对照组(P<0.05)。②呋塞米组肾脏AQP2 mRNA、V2-RmRNA和AQP2蛋白表达较对照组明显增加(P<0.05),而双氢克尿噻组较对照组明显降低(P<0.05),安体舒通组有所减少但无统计学差异。结论三类利尿剂均可显著增加正常大鼠尿液AQP2蛋白的排出。但对正常大鼠肾脏水通道蛋白2基因表达的影响并不相同,双氢克尿噻可以抑制正常大鼠肾内髓质AQP2 mRNA和蛋白的表达,呋塞米能增加正常大鼠肾内髓质AQP2 mRNA和蛋白的表达。

Objective To investigate effects of the furosemide, antisterone and hydrochlorothiazide on expression of kidney aquaporin-2 （AQP2） gene and urine aquaporin-2 excretion in rats. Methods Forty SD rats were randomized into 4 groups, namely the control group, furosemide group, antisterone group and hydrochlorothiazide group with corresponding treatment. Blood and urine samples were collected from the rats for measurement of serum Na^＋, urine volume and urine osmolality during medication. Semi-quantitative RT-PCR was performed to measure kidney inner medullary AQP2 and vasopressin V2-R mRNA. Western blotting was employed to detect kidney inner medullary AQP2 protein expression. Urine AQP2 concentration was measured by enzyme-linked immtmosorbent assay （ELISA）. Result Urine volume and urinary AQP2 excretion were both increased in rats treated with the 3 drugs as compared with that of the control group. However, urine osmolality was lower in furosemide group but higher inhydrochlorothiazide and antisterone groups than in the control group （P〈0.05）. The kidney inner medullary AQP2 mRNA, V2-R mRNA and AQP2 protein expression of furosemide group increased in comparison with that of the control group （P〈0.05）. In hydrochlorothiazide group, however, the above parameters were all decreased （P〈0.05）. Conclusion The three classes of diuretics can all increase the excretion of the urinary AQP2 but have different effects on the inner medullary AQP2 mRNA and protein expression in normal rats. Hydrochlorothiazide reduces kidney AQP2 mRNA and protein expression, while furosemide increased kidney AQP2 gene expression.