模拟失重条件对大鼠肾小管水通道蛋白2表达影响的研究

The study of effect of simulated weightlessness on expression of AQP2 on rats renal tubular

目的探讨模拟失重条件下大鼠肾小管水通道蛋白2(AQP2)表达的变化。方法采用尾部悬吊法建立失重模型。48只健康雄性Wistar大鼠分为对照组及尾吊3 d组、尾吊5 d组、尾吊7 d组、尾吊2周组、尾吊4周组。分别于观察终点处死各组大鼠,处死前留取血尿标本,分别检测肾功能和尿渗透压。剥离肾脏组织,分离肾皮质和髓质。电镜观察肾小管超微结构。Western blot方法检测AQP2的表达。ELISA检测血清中抗利尿激素(ADH)的水平。结果 1电镜下尾吊组大鼠肾脏均表现为肾小管不同程度受损,尾吊5d组大鼠肾小管损伤最严重。2 Western blot显示尾吊组AQP2的表达较对照组均升高,差异有统计学意义(P<0.05,P<0.01),其中尾吊5 d组大鼠肾脏AQP2表达最明显(P<0.01)。3尾吊5 d组尿渗透压显著升高,与其他各组比较差异有统计学意义(P<0.01)。各组间ADH及肾功能指标差异无统计学意义。4 AQP2蛋白表达量与尿渗透压呈正相关性(r=0.468,P=0.003)。结论模拟失重条件能引起大鼠肾小管AQP2表达上升,以尾吊5 d组升高最明显。

Objective To study the expression of AQP2 on rats renal tubular under the condition of simulated weightlessness.Methods Tail-suspension was used to simulate the weightlessness model.48 healthy male wistar rats were randomly divided into control group and experimental group：suspended for 3 days,5 days,7 days,2 weeks,4 weeks.Those rats were killed at corresponding time point.Before killing the blood and urine was stored to examine biochemical of renal function and urine osmolality.The kidney tissues were stripped to cortex and medulla.Renal tubular ultrastructure and the expression of AQP2 were respectively examined with electron microscope and Western blot.The levels of ADH in the serum were detected by ELISA.Results ① Electron microscope results indicated the mainly change of the rat kidney was the renal tubular injury,especially the 5 days in the tail-suspension groups.② Western blot showed that contrasted with the control group,AQP2 changed significantly during simulated weightlessness （P ＜0.05,P ＜0.01）,while in 5 days tai-suspended rats changed the most obviously（P ＜ 0.01）.③ The urine osmolality of the simulated weightlessness 5 days group was significantly higher than the others （P ＜ 0.01）,while for ADH and renal function there was no statistical difference.④ The expression of AQP2 was positively correlated with urine osmolality （r =0.468,P =0.003）.Conclusion The expression of AQP2 on rats renal tubular is increased when induced by simulated weightlessness,and reach peak at 5 days.