阻塞性黄疸时L-精氨酸对肾功能的保护作用

目的：研究阻塞性黄疸（OJ）时，L－精氨酸（L－Arg)对肾功能的保护作用。方法：胆总管结扎大鼠30只，随机分成生理盐水对照（NS）组、L－精氨酸（L－Arg)组和L－硝基精氨酸（L－NNA）组，每组10只。胆总管结扎后第2天起分别腹腔注射1ml NS、1ml L-Arg(500mg/kg)、1ml L-NNA(10mg/kg)，连用9d；假手术（SO）组用1ml NS腹腔注射。观察各组肾功能的变化，同时测定血和肾组织内皮素（ET）、一氧化氮（NO）水平、一氧化氮合酶（NOS）活性和丙二醛（MDA）的含量。并用图像分析检测ET1 mRNA和NOS mRNA表达的部位及量的变化。结果：用L－Arg后，血和肾组织NOS活性增加，肾组织ET1 mRNA表达减少，血和肾组织ET下降，NO升高；同时伴有内生肌酐清除率（Ccr)、肾皮质平均血流（RCBF）的升高，肾组织MDA含量降低。结论：L－Arg通过增强血和肾组织NOS活性来增加体内NO水平、抑制ET1 mRNA表达、降低体内ET水平，从而提高Ccr与RCBF，减轻阻塞性黄疸时的肾功能损伤。

The Protective Effect of L-arginine on Renal Function in Obstructive Jaundice

Objective:To study the protective effect of L-arginine on renal function in obstructive jaundice.Methods:Thirty rats submitted to common bile duct ligation were randomly divided into3groups:saline group(NS),L-Arginine group(L-Arg)and L-NNA group(L-NNA),with10rats in each group;rats of the3groups were administered intraperitoneally1ml saline,1ml L-Arginine(500mg/kg bw)and1ml L-NNA(10mg/kg bw)respectively for nine days,starting from the second day after bile duct ligation.The sham operation group(SO)with10rats was administered1ml NS intraperitoneally too.Renal functions were investigated.The concentrations of ET,NO and MDA,and the activity of NOS in blood and renal tissue were measured.Image analysis was performed to investigate the site and quantity of the expression of ET 1 mRNA and NOS-mRNA in the renal tissue.Results:NOS activity in the plasma and renal tissue increased while the expression of ET 1 mRNA reduced after L-Arg was injected.In the meantime,the concentrations of ET in blood and renal tissue increased while NO reduced followed by an increase in Ccr and RCBF.The concentration of renal MDA,also reduced.Conclusions:By elevating the activity of plasma and renal NOS to increase NO levels and by depressing the expression of ET-1mRNA in kidney to reduce ET levels,L-arginine could improve Ccr and RCBF to ameliorate renal dysfunction in obstructive jaundice.