大鼠肝脏缺血再灌注损伤后水通道蛋白4表达的变化

Changes of aquaporin 4 expression after hepatic ischemia-reperfusion injury in rats

目的:通过建立大鼠肝脏缺血再灌注损伤(IRI)模型,观察水通道蛋白4(AQP4)在肝内胆管细胞的表达变化,并同时检测肝脏功能变化,探讨肝脏IRI与AQP4表达变化的关系。方法:建立大鼠肝脏30 min IRI模型。随机将配对动物分为对照和缺血再灌注2 h、1 d、3 d、7 d组,留取血清标本行间接胆红素(IB)、直接胆红素(DB)及丙氨酸氨基转移酶(ALT)指标检测;留取肝脏标本用于HE染色光镜下观察肝脏病理形态学变化、免疫组化染色观察AQP4表达变化,RT-PCR方法测定AQP4 mRNA表达变化。结果:(1)肝功能变化:缺血再灌注损伤2 h、1 d、3 d组IB、DB及ALT明显升高,与对照组间比较有显著差异(P<0.05),并于术后第1 d达到最高(P<0.05);以后逐渐降低,术后第7 d恢复正常。(2)肝脏病理学变化:术后HE染色可见缺血再灌注可造成大鼠肝组织变性、坏死。(3)免疫组织化学检测肝脏AQP4的变化:缺血再灌注损伤2 h、1 d、3 d组AQP4的表达量较对照组降低(P<0.05),于术后第1 d最低(P<0.05),以后逐渐增高,于术后第7 d恢复正常。(4)肝脏AQP4 mRNA表达变化:缺血再灌注损伤组2 h、1 d、3 d组AQP4 mRNA表达水平较对照组明显降低(P<0.05),于术后第1 d最低,以后又逐渐升高,于术后第7 d恢复正常。结论:大鼠肝脏缺血再灌注损伤后可明显引起肝内胆管上皮细胞AQP4的表达降低,术后第1 d最明显,至术后7 d逐渐恢复正常,此种损害与包括胆红素在内的肝功能损害相对应。

AIM：To study the relationship between the changes of aquaporin 4（AQP4） expression and the liver functions in the process of hepatic ischemia-reperfusion（I/R） injury in rats.METHODS： Forty-eight Wistar rats were used to establish the animal model of hepatic I/R injury.The rats were subject to ischemia for 30 min and were randomly divided into 4 groups according to the time of reperfusion： 2 h group,1 day group,3 days group and 7 days group.The corresponding control animals were also set up.The serum was collected for detecting direct bilirubin（DB）,indirect bilirubin（IB） and alanine transaminase（ALT）.The pathological changes of the liver tissues were observed under microscope with HE staining.The protein expression of AQP4 was measured by the method of immunohistochemistry and the mRNA expression of AQP4 was detected by RT-PCR.RESULTS： Under microscope,degeneration and necrosis of the hepatic cells were observed in the liver tissues in I/R injury groups.Compared with sham operation group,the concentrations of DB,IB and ALT activity in I/R injury groups increased obviously,peaking on the first day after operation,then declining continuously and restoring to the normal levels on the 7th day after operation.The expression of AQP4 were significantly decreased in I/R injury animals in 2 h group,1 day group and 3 days group,and reached the minimum level on the first day.The mRNA expression levels of AQP4 were also deceased in hepatic I/R injury rats in 2 h group,1 day group and 3 days group,and reached the minimum level on the first day after operation,then increased slowly and restored to the normal levels on the 7th day after operation.CONCLUSION： Hepatic ischemia-reperfusion induces a decrease in AQP4 expression and impairs the liver functions,indicating an important role of AQP4 in the pathogenesis of liver ischemia-reperfusion injury.