卡托普利和洛沙坦对大鼠肾脏水通道蛋白-2 mRNA和尿液水通道蛋白-2的影响

目的 探讨卡托普利和洛沙坦对正常大鼠肾脏水通道蛋白-2(AOP2)mRNA表达的影响及尿液水通道蛋白-2浓度的改变。方法 30只健康大鼠随机分成3组；正常对照组，卡托普利组．洛沙坦组。经用药后观察血Na^+、尿量以及尿渗量水平，用RT-PCR半定量检测肾内髓质AOP2及血管加压素2型(V2)受体mRNA水平，用酶联免疫吸附测定法检测尿液AOP2浓度。结果 卡托普利组与洛沙坦组大鼠尿量均较正常组显著增多，卡托普利组尿渗量低于洛沙坦组和正常组，但尿液中AQP2浓度却高于洛沙坦组和正常组。RT-PCR半定量显示卡托普利组AOP2 mRNA较正常组显著降低(P<0．05)，V2受体mRNA没有显著差别。结论 卡托普利可以抑制正常大鼠肾内髓质AOP2 mRNA的表达，同时促进肾内AOP2经尿液排出。

Effects of captopril and losartan on expression of kidney aquaporin-2 mRNA and urine aquaporin-2 excretion in rats]

OBJECTIVE: To investigate effects of captopril and losartan on the expression of kidney aquaporin-2 (AQP2) mRNA and the excretion of urine AQP2 in rats. METHODS: Thirty healthy rats were randomized into 3 groups, namely the control group, captopril group and losartan group, respectively. Blood and urine samples were collected from the rats for detecting serum Na(+), urine volume and urine osmolality in the course of medication. Urine AQP2 concentration was measured by enzyme-linked immunosorbent assay (ELISA). Semi-quantitative RT-PCR was performed for measurement of kidney inner medullary AQP2 and vasopressin V(2) receptor mRNA. RESULTS: Urine volume was increased in rats of captopril and losartan groups as compared with that of the control group. However, urine osmolality was lower in captopril group than in the other two groups (P<0.05). RT-PCR revealed decreased quantity of the inner medullary AQP2 mRNA of the captopril group than that of the other two groups, but the quantity of V(2) receptor mRNA did not differ significantly between the 3 groups. Urine AQP2 concentration was significantly higher in captopril group than in the control (P<0.05) and losartan groups (P0<0.01). CONCLUSION: Captopril can reduce the expression of the kidney inner medullary AQP2 mRNA and accelerate the excretion of the urine AQP2 in normal rats.