肿瘤坏死因子预处理减轻大鼠肝脏缺血再灌注损伤

Tumor necrosis factor-alpha preconditioning alleviated the intensity of hepatic ischemia-reperfusion injury in rats

目的 探讨肿瘤坏死因子-α（TNF-α）预处理对大鼠肝脏缺血再灌注损伤（HIRI）的影响及其机制,以及TNF-α预处理效果是否与剂量有关.方法 将40只Wistar大鼠随机分为4组：假手术组（SO组）仅行开腹及肝门游离;缺血再灌注模型组（IR组）采用Pringle＆#39;s法阻断肝门30 min,再灌注6h;低剂量TNF-α预处理组（LTPC组）术前30 min给予TNF-α 1 μg/kg腹腔注射,此后操作同IR组;高剂量TNF-α预处理组（HTPC组）,术前30 min给予TNF-α2 μg/kg腹腔注射,此后操作同IR组.检测血清谷丙转氨酶（ALT）和谷草转氨酶（AST）,采用免疫组织化学法检测B细胞淋巴瘤/白血病-2（bcl-2）蛋白和核因子κB（NF-κB） p65蛋白表达,以及肝细胞凋亡指数（AI）.结果 与IR组[（642.8±149.3）、（730.6±103.0）U/L]比较,血清ALT、AST水平在LTPC组[（336.8±79.4）、（392.7±109.3） U/L]和HTPC组[（349.8±98.4）、（425.5±101.1） U/L]明显降低（P＜0.05）;肝细胞凋亡评分AI降低（P＜0.05）,肝组织内bcl-2蛋白阳性表达升高（P＞0.05）,而NF-κB p65阳性表达降低（P＜0.05）.上述指标在LTPC组与HTPC组比较差异无统计学意义（P＞0.05）.结论 低剂量TNF-α预处理通过抑制NF-κB p65蛋白表达、激活凋亡抑制基因bcl-2蛋白表达,减轻大鼠HIRI.

Objective To study the protective effect of tumor necrosis factor （TNF）-α preconditioning on hepatic ischemia-reperfusion injury （IRI） and the underlying mechanisms,and the relationship between dose and effect.Methods Fourty healthy male Wistar rats were randomly divided into four groups：sham-operated （SO） group,ischemia-reperfusion （IR） group （total inflow occlusion for 30 min）,low-dose TNF-α preconditioning （LTPC） group （intraperitoneal injection of 1 μg/kg TNF-α 30 min prior to IR） and high-dose TNF-α preconditioning （HTPC） group （intraperitoneal injection of 2 μg/kg TNF-α 30 min prior to IR）.The samples of blood and hepatic tissue were taken after the experiment.The protein levels of nuclear factor-κB （NF-κB） p65 and B cell lymphoma/leukemia-2 （bcl-2） in the hepatic tissue were detected by immunohistochemistry.Results There was significant difference （P 〈 0.05） between the IR group and the TPC groups in the levels of ALT and AST,the expression of NF-κB p65 and bcl-2,and apoptosis index in hepatic tissues.There was no significance difference （P 〉 0.05） between the LTPC group and the HTPC group.Conclusion Low-dose TNF-α preconditioning decreased the intensity of hepatic IRI by inducing a decrease in the NF-κB p65 expression and an increase in the bcl-2 expression.