胱硫醚-γ-裂解酶/硫化氢系统在大鼠肝脏缺血再灌注损伤中的保护作用

目的 研究胱硫醚-γ-裂解酶/硫化氢(CSE/H2S)系统在大鼠肝脏缺血再灌注损伤中的保护作用,探讨其病理生理学意义.方法 将72只健康Wistar大鼠平均分为4组:假手术组(sham组)、缺血再灌注组(IR组)、IR+硫氢化钠组(IR+NaHS组)、IR+DL-炔丙基甘氨酸组(IR+PAG组).采用Pringle法夹闭30 min后恢复血流建立缺血再灌注损伤模型.再灌注后1、3、6 h取材检测血清H2S水平和CSE活性、肿瘤坏死因子(TNF)-α和白介素(IL)-10水平、肝组织中凋亡蛋白TNF-α表达、观察细胞凋亡状态以及肝脏组织学变化.结果 与sham组比较,IR组各时间点的血清H2S水平以及CSE活性均明显上升(P＜0.05),血清炎性细胞因子含量明显增高(P＜0.01),凋亡蛋白TNF-α表达也显著增加(P＜0.05).NaHS的应用可显著降低缺血再灌注后血清中炎性因子水平(P＜0.01)、减少细胞凋亡蛋白表达(P＜0.05)及减轻肝脏损伤(P＜0.05),而应用抑制剂PAG则结果相反.结论 CSE/H2S系统参与肝脏缺血再灌注损伤的内源性防御体系,应用外源性H2S通过参与炎症反应、减轻肝细胞损伤、抑制凋亡,从而在肝脏缺血再灌注损伤中起到保护作用.

Protection of CSE/H2S system in hepatic ischemia reperfusion injury in rats

Objective To study the protective function and pathophysiology of cystathionine gammalyase (CSE)/hydrogen sulfide( H2S) system in hepatic ischemia-reperfusion injury(HIRI) in rats. Methods Wistar rats were randomly distributed into sham group (n = 18), ischemia-reperfusion (IR) group (n = 18),IR + NarHS group( n = 18 ) and IR + DL-propargylglycine (PAG) group ( n = 18 ). The hepatic IR model was established by Pringle's hepatic vascular occlusion. At each of the indicated time points( 1,3 and 6 hours after IR), the serum levels of H2S and the hepatic CSE activity were measured. The serum levels of inflammtory factors,including TNF-α, IL-10 were determined by ELISA methods. The expression of apoptotic protein,TNF-α,in liver tissue was tested by Western blot assay,cell apoptosis was examined by TUNEL and the histological changes were examined in each group. Results The serum levels of H2S and CSE activity were significantly increased in group IR compared with group sham at all indicated time points( P ＜ 0.05 ).The serum level of inflammatory factors(P＜ 0.01) and the hepatic expression of TN F-α protein(P＜ 0.05)were elevated obviously in group IR than that in group sham. Administration of NaHS could reduce the production of inflammatory factors in serum (P＜0.01), inhibit hepatic protein expression of TNF-α(P＜0.05) and attenuate the liver histological scores of IR injury (P＜0.05), whereas PAG aggravated them. Conclusion The endogenous CSE/H2S system maybe involved in the pathogenesis of hepatic IR injury,which suggests that CSE/H2S system can protect liver from IR injury in rats by intervening in inflammatory reaction, attenuating the injury severity and inhibiting expression of apoptofic protein TNF-α.