硫氧还蛋白系统在硫化氢抗大鼠肝缺血再灌注损伤中的变化

Alternation of thioredoxin system in postconditioning with hydrogen sulfide against hepatic ischemia-reperfusion injury in rats

目的观察硫氧还蛋白（Trx）系统在硫化氢（H2S）抗大鼠肝缺血再灌注损伤中的变化。方法以硫化氢钠（NaHS）作为H2S供体，采用随机数字表法将18只SD大鼠随机分为3组：假手术组（Sham组）、肝缺血再灌注组（IR组）、硫化氢钠处理组（NaHS组）。建立70％肝缺血再灌注模型，NaHS组于再灌注前5min腹腔注射NaHS28μmol／kg。各组于再灌注后6h取血，测定血清丙氨酸转氨酶（ALT）、天冬氨酸转氨酶（AST）活性；取肝叶HE染色观察其组织形态变化；取肝组织采用双抗体夹心酶联免疫吸附（ELISA）法检测硫氧还蛋白酶（Trx）、硫氧还蛋白还原酶（TrxR）活性，免疫印迹（Westernblot）技术检测Trx系统蛋白和硫氧还蛋白相互作用蛋白（TXNIP）表达。结果与IR组比较，NaHS组大鼠血清中ALT、AST水平下降，病理损害明显减轻。与Sham组比较，IR组Th活性下降和Trxl蛋白表达下调，TXNIP蛋白表达上调（P〈0．05）；与IR组比较，NaHS组Trx活性升高和Trxl蛋白表达上调，TXNIP蛋白表达下调（P〈0．05），表明H2S后处理可减少对Trx的抑制提高组织的抗氧化能力。结论Trx系统参与肝缺血再灌注损伤的发生发展，H2S后处理增强了细胞Trx系统的抗氧化损伤能力，发挥保护作用。

Objective To explore the relationship between the protection of hydrogen sulfide （ H2S） against hepatic ischemia-reperfusion injury and thioredoxin system in rats. Methods Eighteen adult rats were divided randomly into 3 groups, i.e. sham, ischemia-reperfusion （IR） and sodium hydrogen sulfide （NariS）. The rats in the IR and NariS groups were subjected to isehemia for 60 rain and followed by reperfusion for 6 hours. In the NariS group, there was an intraperltoneal dosing of NariS （28 ixmol/kg） at 5 min pre-reperfusion. Blood samples were collected for the measurements of alanine transaminase （ALT） and aspartate transaminase （AST） . Liver tissue samples were collected for measurements of Trx and TrxR activity by enzyme-linked immunosorbent assay （ ELISA）, Western blot detection of Trx system proteins and thioredoxin interacting protein （TXNIP） expression. Hematoxylin-eosin staining was used to observe the hepatic histopathological changes. Results Compared with the sham group, increased activities of ALT and AST were found in the IR group, accompanied by aggravated pathological injury. In addition, Naris administrated at pre-reperfusion could alleviate hepatic injury. Compared with the sham group, the IR group had decreased Trx activity and Trxl protein expression and increased TXNIP protein expression （P 〈 0. 05） while the Naris group had increased Trx activity and Trxl protein expression and decreased TXNIP protein expression （P 〈 0. 05 ）. It indicated that the posteonditioning with H2S could reduce the inhibition of Trx system and boost tissue antioxidant capacity. Conclusion Hydrogen sulfide posteonditioning can enhance the cellular Trx system and play a protective role in hepatic isehemia-reperfusion injury.