外源性H2S吸入对大鼠肢体缺血／再灌注后心肌损伤的保护作用研究

Inhalation of hydrogen sulfide prevents myocardial injury following hindlimb ischemia reperfusion

目的研究外源性H2S吸入对大鼠双下肢缺血/再灌注后心肌损伤的保护作用。方法雄性Wistar大鼠23只,随机分为三组:①正常对照组(C组,8只);②缺血/再灌注组(I/R组,8只):应用止血带结扎构建大鼠双下肢缺血/再灌注模型,缺血4 h再灌注4 h。③H2S吸入组(H2S组,7只):大鼠双下肢缺血4 h,再灌注时给予含80 ppm H2S的合成空气持续吸入4 h。观察各组大鼠心肌病理、血浆H2S、肌酸激酶同工酶(CK-MB)、肌钙蛋白-T(TnT)、髓过氧化物酶(MPO)、肿瘤坏死因子-α(TNF-α)水平的变化及心肌胱硫醚-γ-裂解酶(CSE)活性、MPO、TNF-α水平的变化。以免疫组化法观察心肌细胞TNF-α的表达。结果与C组比较,I/R组血浆CK-MB、TnT、MPO、TNF-α及心肌MPO、TNF-α水平明显上升(P<0.05),血浆H2S及心肌CSE活性明显下降(P<0.05),H2S吸入后血浆H2S及心肌CSE活性明显升高;同时,血浆CK-MB、TnT、MPO、TNF-α及心肌MPO、TNF-α水平明显降低(P<0.05)。心肌病理提示I/R组心肌明显肿胀、血管充血,心肌细胞间可见明显分叶核粒细胞浸润,红细胞漏出增多,H2S吸入后心肌损伤明显减轻。心肌TNF-α免疫组化提示I/R组心肌胞浆棕色染色颗粒较C组明显增多,H2S吸入后心肌胞浆棕色染色颗粒明显减少。结论外源性H2S吸入可以通过降低炎细胞浸润及炎性细胞因子激活而对骨骼肌缺血/再灌注的心肌损伤发挥保护作用。

Objective To observe the protective effects of exogenous hydrogen sulfide（ H2 S ） on the myocardial injury following hindlimb ischemia reperfusion （IR）. Methods We have established the model of bilateral hindlimb I/R in rats by using a tourniquet. Twenty - three Wistar rats were divided into 3 groups randomly： Group normal, Group I/R： 4 h repeffusion following 4 h ischemia, Group H2S： I/R ＋ inhaling 80 ppm H2S for 4 h. The pathologic changes in the myocardium were observed. The plasma levels of H2S, CK - MB, TnT, myeloperoxidase （MPO） , tumor necrosis factor - α （ TNF - α） in each group were measured. The CSE activity and the levels of MPO, TNF - α in myocardium were detected. Immunohistochemistry technique was used to determine expression of TNF - α in myocardium. Results Histopathologic results indicated significant myocardial injuryafter hindlimb ischemia repeffusion, which was markedly alleviated in Group H2S. Compared with Group normal, the plasma H2 S level and the myocardial CSE activity were decreased obviously in Group I/R （ P 〈 0. 05 ） , the plasma levels of CK - MB, TnT, MPO, TNF - c~ and the myocardial levels of MPO, TNF - oL were significantly increased in Group I/ R （ P 〈 0. 05 ）. After inhaling 80 ppm H2 S, the plasma H2 S level and the myocardial CSE activity were significantly higher, the plasma levels of CK - MB, TnT, MPO, TNF - α and the myocardial levels of MPO, TNF -α were markedly decreased （ P 〈 0. 05 ）. hnmunohistochemical results showed that the positive signals of TNF-α was significantly decreased in Group H2S compared with Group I/R. Conclusions Ex- ogenous H2S can protect myocardial injury following hindlimb ischemia reperfusion through inhibiting the production of neutrophils and inflammatory cytokines.