L-精氨酸对梗阻性黄疸大鼠肾的保护作用

The protective effect of L-arginine on kidneys of rats with obstructive jaundice

目的 :探套 L -精氨酸对于梗阻性黄疸大鼠肾的影响及相应的机制。 方法 :采用双重结扎大鼠胆总管造成梗阻性黄疸模型 ,14天后 ,不同组大鼠分别给予 L-精氨酸 (L- Arg) [5 0 0 mg/ (kg· d) ]或 L-精氨酸甲酯 (L- NAME)[10 mg/ (kg· d) ],2 1天后 ,测定肾组织匀浆中一氧化氮 (NO)、超氧化物歧化酶 (SOD)、丙二醛 (MDA)的含量以及肾功能改变 ,采用 Western杂交技术比较不同组大鼠肾热休克蛋白 70 (HSP70 )的表达情况 ,并观察肾形态学改变。 结果 :胆道梗阻后 2 1天 ,肾组织中 NO及 MDA含量均增高 ,而 SOD水平下降 ,肾功能受损 ,给予 L - Arg组大鼠肾组织中 NO含量较单纯梗阻性黄疸组增加显著 (P<0 .0 1) ,而 SOD活性增高 (P<0 .0 1) ,MDA水平降低 (P<0 .0 5 ) ,肾功能改善 ,而且 HSP70表达明显增强。肾组织结构损伤减轻。相反 ,给予 L- NAME组大鼠肾组织 NO含量与单纯梗阻性黄疸组相比 ,明显降低 (P<0 .0 5 ) ;SOD活性无明显增高 ,MDA水平亦无明显降低 ,肾功能未见改善 ,反而有损害加重趋势 ,HSP70表达无明显增加 ,肾组织损伤未见减轻。 结论 :L - Arg对梗阻性黄疸大鼠肾可起保护作用 ,这可能是通过 L- Arg增加 NO的通路实现的。

Objectives:To study the effect of L arginine(L Arg) on kidneys of rats with obstructive jaundice. Methods:The rats rendered jaundiced by ligating the common bile duct.14 days later,we administrated L Arg or L N G nitroarginine methyl(L NAME)to different groups respectively for 7 days.On the day 21 after bile duct ligation,the amount of nitric oxide(NO),malondrialdehyde(MDA),and superoxide dismutase(SOD) were determined in the kidney,and the changes of the renal function were assessed.We also observed the morphological changes of kidneys,and compared the expression of heat shock protein 70(Hsp70) of the kidney in every group by western blotting. Results:In the group with obstructive jaundice,the amount of NO and MDA increased,SOD decreased,and the renal function was damaged on the day 21 after bile duct ligation,when compared with the sham operation group.In the group receiving L Arg,the amount of NO and SOD increased significantly( P <0.01),MDA decreased( P <0.05),the expression of Hsp70 in the kidney was more obvious and the damage in the nephric tissue was alleviated.The amount of NO decreased significanlty( P <0.05) in the group receiving L NAME. Conclusions:L Arg may protect against the renal impairment in rats with obstructive jaundice through L Arg-NO pathway.