水通道蛋白2在胆总管结扎大鼠肝硬化肾组织中的表达及丹参注射液对其表达的影响

目的:探讨胆总管结扎(bile duct ligation,BDL)大鼠肝硬化不同阶段肾组织中水通道蛋白2(aquaporins-2,AQP2)表达的变化;用丹参注射液干预肝硬化腹水大鼠,观察丹参注射液对其表达的影响.方法:将70只♂SD大鼠随机分成假手术组、模型组.模型组分别于结扎后1、2、3、4wk麻醉10只动物.假手术组与4wk模型组同批麻醉.4wk末时,再从剩余存活造模大鼠中,随机选取16只腹腔穿刺证实有腹水的大鼠,随机分为治疗组和对照组.从造模第5周开始进行治疗观察.治疗组给予丹参注射液2mL腹腔注射,1次/d,连用2wk.对照组给予蒸馏水2mL腹腔注射,1次/d,连用2wk,6wk末2组同批麻醉.采用HE染色、Masson三色染色确定模型建立情况;肾脏组织标本采用HE染色,光镜下观察组织学变化,应用免疫组织化学方法测定AQP2的表达及分布.结果:造模1-4wk大鼠肾组织AQP2的阳性染色平均吸光度A值(皮质:0.4703±0.0313,0.4832±0.0212,0.5081±0.0417,0.6802±0.0531;髓质:0.4320±0.0237,0.4724±0.0284,0.4796±0.0451,0.5187±0.0612)均高于假手术组(皮质:0.4197±0.0295;髓质:0.4139±0.0152,P<0.05),提示肝硬化进程中,AQP2在肾皮质和肾髓质的表达均逐渐增强.治疗组(皮质:0.4233±0.0521,髓质:0.4158±0.0413)大鼠肾组织AQP2的阳性染色平均A值显著低于对照组(皮质:0.5536±0.0476,髓质:0.4764±0.0536,P<0.05).结论:以BDL法制备的大鼠肝硬化模型中存在着肾脏AQP2表达的上调,提示在肝硬化进程中,肾脏集合管可能参与了水重吸收的增加;而丹参注射液可以下调肝硬化腹水大鼠肾脏AQP2的高表达.

Salvia miltiorrhiza reduces expression of aquaporin 2 in kidney tissue of cirrhotic rats

AIM:To detect the expression of aquaporin 2(AQP2) in kidney tissue of rats with BDL-induced cirrhosis and to observe the effect of treatment with salvia miltiorrhiza on AQP2 expression in this animal model.METHODS:Seventy SD rats were randomly divided into sham operation group and model group.To induce biliary cirrhosis,SD rats underwent double ligation and sectioning of the common bile duct(BDL).Animals in the model group were sacrificed at weeks 1,2,3 and 4.At week 5,the model group was divided into two groups:treatment group and control group.Rats in the treatment group were treated with salvia miltiorrhiza,while those in the control group was treated with vehicle.Liver histopathological changes were evaluated by hematoxylin and eosin(H&E) staining and Masson’s trichrome staining.Kidney histopathological changes were evaluated by H&E staining.Immunohistochemistry was employed to investigate the expression of AQP2 in kidney tissue of cirrhotic rats.RESULTS:With the progression of hepatic cirrhosis,the expression of AQP2 increased gradually.The optical density(OD) of renal AQP2 at weeks 1 to 4 was significantly higher in the model group than in the sham operation group(cortex:0.4703 ± 0.0313,0.4832 ± 0.0212,0.5081 ± 0.0417,0.6802 ± 0.0531 vs 0.4197 ± 0.0295;medulla:0.4320 ± 0.0237,0.4724 ± 0.0284,0.4796 ± 0.0451,0.5187 ± 0.0612 vs 0.4139 ± 0.0152;all P < 0.05).The expression of AQP2 in the control group was higher than that in the treatment group.The OD of renal AQP2 in the control group was significantly higher than that in the treatment group(cortex:0.5536 ± 0.0476 vs 0.4233 ± 0.0521;medulla:0.4764 ± 0.0536 vs 0.4158 ± 0.0413,both P < 0.05).CONCLUSION:The expression of AQP2 is up-regulated in kidney tissue of cirrhotic rats.Salvia miltiorrhiza treatment reduced the expression of AQP2 in kidney tissue of cirrhotic rats.