外源性硫化氢对脑缺血再灌注损伤大鼠氧化应激的影响

Effect of exogenous hydrogen sulfide on oxidative stress in rats with cerebral ischemia-reperfusion injury

摘要:

目的 探究外源性硫化氢［以硫氢化钠（NaHS）为供体］对大鼠大脑中动脉闭塞（MACO）模型的神经保护效应及机制。方法 将60只Sprague-Dawley大鼠均分为假手术组、缺血再灌注（I/R）模型组、NaHS治疗组。假手术组仅不栓塞大脑中动脉，余操作同I/R模型组（MACO模型）；NaHS治疗组在脑缺血后再灌注前20 min腹腔注射6.4 mg/kg的NaHS。通过2，3，5-三苯基氯化四氮唑染色检测脑组织梗死体积，酶联免疫吸附分析测定超氧化物歧化酶（SOD）活性及丙二醛（MDA）含量，实时定量聚合酶链反应检测Nrf2 mRNA表达，免疫印迹法分析核转录因子红系2相关因子2（Nrf2）蛋白磷酸化程度。结果 与假手术组相比，I/R模型组神经功能缺损评分增加，脑梗死体积增加，SOD活性升高，MDA含量升高，缺血周边区Nrf2 mRNA表达上调，p-Nrf2/Nrf2蛋白比值升高（均P<0.05）。与I/R模型组相比，NaHS治疗组神经功能缺损评分降低，脑梗死体积减小，SOD活性增强，MDA含量降低，Nrf2 mRNA表达升高，p-Nrf2/Nrf2比值下降（均P<0.05）。结论 外源性硫化氢能抑制脑I/R氧化应激过度激活，减小脑组织梗死体积，发挥神经保护作用，为硫化氢用于缺血性脑卒中的临床干预提供了理论依据。

Abstract:

Objective To investigate the neuroprotective effect and mechanism of exogenous hydrogen sulfide ［using sodium hydrosulfide （NaHS） as a donor］ in a rat model of middle cerebral artery occlusion （MCAO）.Methods A total of 60 Sprague-Dawley rats were randomly divided into sham-operation group， cerebral ischemia/reperfusion （I/R） model group， and NaHS treatment group. The rats in the sham-operation group were given the same treatment as the model group except for middle cerebral artery occlusion， and those in the NaHS treatment group were given intraperitoneal injection of 6.4 mg/kg NaHS 20 minutes before reperfusion after cerebral ischemia. 2，3，5-triphenyltetrazolium chloride （TTC） staining was used to measure cerebral infarct volume； ELISA was used to measure the activity of superoxide dismutase （SOD） and the content of malondialdehyde （MDA）； quantitative real-time PCR was used to measure the mRNA expression level of Nrf2， and Western blotting was used to measure the phosphorylation level of Nrf2 protein.Results Compared with the sham-operation group， the I/R model group had significant increases in neurological deficit score and cerebral infarct volume， a significant increase in the activity of SOD， and significant increases in the content of MDA， the mRNA expression level of Nrf2 in the peri-ischemic area， and p-Nrf2/Nrf2 protein ratio （all P<0.05）. Compared with the I/R model group， the NaHS treatment group had significant reductions in neurological deficit score and cerebral infarct volume， a significant increase in the activity of SOD， significant reductions in the content of MDA， significant increase in the mRNA expression level of Nrf2， and significant reductions in the p-Nrf2/Nrf2 ratio （all P<0.05）.Conclusions Exogenous hydrogen sulfide can inhibit the excessive activation of oxidative stress in cerebral I/R injury， reduce cerebral infarct volume， and exert a neuroprotective effect， which provides a theoretical basis for the application of hydrogen sulfide in the clinical intervention of ischemic stroke.