硫化氢对大鼠心肌缺血/再灌注损伤的保护作用及其对c-Fos蛋白表达的影响(英文)

H_2S protects myocardium against ischemia/reperfusion injury and its effect on c-Fos protein expression in rats

为探讨硫化氢(hydrogen sulfide,H2S)对大鼠心肌缺血/再灌注(ischemia/reperfusion,I/R)损伤的保护作用及机制,雄性Sprague-Dawley大鼠被随机分为对照组(假手术组)、I/R组、2.8μmol/kg体重NaHS干预组、14μmol/kg体重NaHS干预组。结扎冠状动脉前降支30min后,松扎再灌注60min,心电图II导联检测和TTC染色测定心肌梗死面积评价制作的心肌I/R模型;测定血浆中H2S浓度变化;监测血流动力学指标(LVSP,LV±dp/dtmax);HE染色和透射电镜观察心肌形态学改变;免疫组织化学方法测定心肌组织中c-Fos蛋白表达。结果显示:心肌I/R后血浆中H2S浓度明显低于对照组[(30.32±5.26)vs(58.28±7.86)μmol/L,P<0.05];2.8和14μmol/kg体重NaHS均可显著改善I/R引起的心功能改变,且14μmol/kg体重NaHS较2.8μmol/kg体重NaHS作用强;14μmol/kg体重NaHS明显减轻心肌形态学及超微结构损伤,同时降低大鼠I/R心肌组织中c-Fos蛋白表达(0.20±0.06vs0.32±0.10,P<0.05)。以上结果提示,H2S对大鼠心肌的I/R损伤有保护作用,这可能与其降低c-Fos蛋白表达有关。

The present study was aimed to study the effect of hydrogen sulfide （H2S） on rat myocardial ischemia/reperfusion （I/R） injury and whether the effect is mediated by c-Fos protein expression. Male Sprague-Dawley rats were randomly divided into 4 groups： Control group： sham treatment; I/R group： the rat anterior descending branch of left coronary artery was occluded for 30 min and then released to allow reperfusion for 60 min; NariS （exogenous H2S donor） groups： the rats were pretreated with NariS at 2.8 μmol/kg body weight and 14 μmol/kg body weight （i.v.）, respectively, before I/R treatment. Hemodynamics （LVSE LV±dp/dtmax） and electrocardiogram （ECG, lead Ⅱ） were monitored continuously with multi-channel physiological signal analysis system after reperfusion. Myocardial infarct size was measured using triphenyltetrazolium chloride （TTC） staining. H2S concentration in the plasma was determined with a spectrophotometer. Morphological and ultrastructural changes in myocardial tissue wereevaluated by HE staining and by a transmission electron microscope. The evaluation of c-Fos protein expression in myocardial tissue was performed by immunohistological staining. The results showed that H2S concentration in rat plasma in I/R group was significantly decreased compared with that in the control group [（30.32±5.26） vs （58.28±7.86） μmol/L, P〈0.05]. Naris at 2.8 and 14 μmol/kg body weight reduced the changes in LVSP, LV±dp/dtmax in rat myocardium induced by I/R injury. The values of LVSP, ±dp/dtmax and ±dp/dtmax at 60 min during myocardial reperfusion were enhanced from （75.93±1. 10）%, （66.27±4.78）% and （66.01±4.79）% in I/R group to （84.34±2.24）%, （76.38±1.93）% and （75.47±5.29）% in 2.8 μmol/kg body weight Naris group （P〈0.05, P〈0.01, n=6）, （88.40±2.88）%, （80.10±2.09）% and （80.48±6.20）% in 14 μmol/kg body weight Naris group （P〈0.01, n=6）, respectively. Compared with that in 2.8 μmol/kg body weight NariS group, the enhancing effect was more prominent in 14 μmol/kg body weight NariS group. NariS at 14 μmol/kg body weight markedly alleviated the injury in morphological changes and decreased c-Fos protein expression in myocardial tissue compared with that in I/R group （0.20±0.06 vs 0.32±0.10, P〈0.05）. These results suggest that H2S protects myocardium against I/R injury and this protective effect may be related to the down-regulation of c-Fos protein expression.