硫化氢对大鼠肠缺血∕再灌注损伤中肠黏膜上皮细胞凋亡的影响

Effects of hydrogen sulfide on apoptosis of intestinal mucosal epithelial cells during ischemia / reperfusion in rats

目的研究外源性硫化氢(H2S)对缺血/再灌注中肠黏膜上皮细胞凋亡的影响,并探讨其作用机制。方法分离肠系膜上动脉,用血管夹夹闭其根部1 h,随后松夹形成再灌注,建立在体肠缺血/再灌注损伤模型。实验设3个组:假手术对照组(C组)、缺血/再灌注组(I/R组)和缺血/再灌注硫化氢预处理组(Na HS组),24只健康清洁级SD大鼠随机分到以上各组,每组8只。再灌注2 h检测各组血清和小肠组织上清液超氧化物歧化酶(SOD)、丙二醛(MDA)及谷甘肽过氧化物酶(GSH-Px)水平,HE染色光镜下观察小肠黏膜组织病理学改变,使用原位缺口末端标记(TUNEL)法进行细胞凋亡检测,Western blot法检测caspase-3蛋白的表达情况。结果与C组相比,I/R组和Na HS组的小肠黏膜和腺体损伤明显,血清及小肠组织SOD、GSH-Px水平明显降低,细胞凋亡指数(AI)和MDA水平明显升高,回肠组织caspase-3蛋白表达明显增加;而Na HS组和I/R组比较,损伤明显减轻,SOD和GSH-Px水平显著提高,细胞凋亡指数(AI)、MDA水平和caspase-3蛋白的表达水平均显著降低(P<0.01)。结论 H2S在一定程度上保护了缺血/再灌注后的肠黏膜组织,减轻了肠黏膜上皮细胞的凋亡,该作用可能与减轻缺血/再灌注过程中的氧化应激反应有关。

Objective To explore the effects of hydrogen sulfide（ H2S） on apoptosis of intestinal mucosal epithelial cells during ischemia / reperfusion in rats and discuss the potential mechanisms. Methods The superior mesenteric artery was separated and blocked from the root using vascular clamp for 1 hour,then remove the clamp to restore blood supply,which accomplish duplicating intestinal ischemia / reperfusion animal model. Twenty-four male SD rats were randomly divided into3 groups with 8 rats in each group： Sham-operation control group（ C group）,Ischemia / reperfusion group（ I / R group） and H2 S pretreatment group（ Na HS group）. Collect blood and intestinal tissue samples to assay the levels of superoxidase dismutase（ SOD）,malondialdehyde（ MDA） and glutathione peroxidase（ GSH-Px） after 2 hour reperfusion. The intestinal mucosal injury and histological alteration under through HE staining was observed. TUNEL method was used to detect apoptosis cells. Caspase-3 protein was measured by Western blot. Results Compared with C group,the damage of small intestinal mucosal tissue and gland was obvious in both I / R group and Na HS group,the levels of SOD and GSH-Px in serum and intestinal tissue was significantly decreased,cell apoptosis index（ AI）,MDA levels and caspase-3 protein expression were increased significantly. H2 S pretreatment markedly alleviated the pathological damage of small intestinal mucosal tissue,reduced the number of apoptosis cells,decreased the levels of MDA and caspase-3 protein expression,and promoted the levels of SOD and GSH-Px（ P〈0. 01）,as compared with I / R group. Conclusion H2 S can relieve the injury of intestinal mucosal tissues after ischemia / reperfusion,reduce the intestinal mucosal epithelial cells apoptosis,which maybe relates to its relieving the oxidative stress reaction during ischemia / reperfusion.