甲烷盐水在脓毒症大鼠肠道损伤中的保护作用

Protective effects of methane saline on intestinal injury in septic rats

目的观察甲烷盐水对脓毒症大鼠肠道损伤的保护作用,并探讨其可能的作用机制。方法雄性SD大鼠128只,体重220～280 g,8～10周龄,采用随机数字表法,分为4组(n=32):假手术组(Sham组)、脓毒症组(Sepsis组)、甲烷盐水组(Sham+MS组)和脓毒症甲烷盐水组(Sepsis+MS组)。采用盲肠结扎穿孔(CLP)法制备脓毒症模型。CLP术后0.5 h和12 h时Sham+MS组和Sepsis+MS组腹腔注入10%甲烷盐水10 mL/kg。每组取20只大鼠,观察术后7 d内的生存率。CLP术后6、18 h处死大鼠,取中段空肠染色并作组织病理学Chiu′S评分;检测各组大鼠肠组织超氧化物歧化酶(SOD)、髓组织过氧化物酶含量(MPO)、肿瘤坏死因子-α(TNF-α)和白细胞介素-10(IL-10)水平,采用Western blot测肠道组织核因子E2相关因子2(Nrf2)、血红素氧合酶-1(HO-1)和肠道组织紧密连接蛋白(Occludin)的蛋白表达。结果与Sham组比较,Sepsis组和Sepsis+MS组肠道组织病理学Chiu′S评分升高,Nrf2、HO-1和Occludin蛋白表达上调(P<0.05),Sham+MS组上述各指标差异无统计学意义(P>0.05);与Sepsis组比较,Sepsis+MS组肠道组织病理学Chiu′S评分降低,Nrf2、HO-1和Occludin蛋白表达上调,差异有统计学意义(P<0.05)。结论甲烷盐水治疗减轻脓毒症大鼠肠道组织损伤的机制与激活Nrf2/ARE通路上调HO-1促进肠道Occludin表达有关。

Objective To investigate the role of HO-1 on methane saline treatment for intestinal injury caused by sepsis and to explore its possible mechanism. Methods A total of 128 male SD rats(weighing 220-260 g and 8-10 weeks old) were randomly divided into 4 groups(n=32), Group Sham, Group Sepsis, Group Sham+MS and Group Sepsis+MS. Sepsis model was established by cecal ligation and puncture(CLP). Half hour and 12 h after CLP, rats in Group Sham+MS and Sepsis+MS were intraperitoneally injected with 10% methane saline(10 mL/kg). Twenty rats in each group were used to observe the survival rate within 7 days after operation. CLP rats were sacrificed 6 h and 18 h after operation, and the jejunum tissues were collected for evaluation of histolopathological Chiu′s score and intestinal permeability. The peroxidation of superoxide dismutase(SOD), myeloperoxidase(MPO), tumor necrosis factor alpha(TNF-α) and interleukin-10(IL-10) in the intestinal mucosa were detected by Elisa. The expression of Nrf2, HO-1 and tight junction protein(Occludin) were assessed by Western blot.Results Compared with Group Sham, the Chiu′s scores were significantly increased, while the expression of Nrf2, HO-1 and Occludin proteins were significantly up-regulated in Group Sepsis and Sepsis+MS(P<0.05). Compared with Group Sepsis, Chiu′s score in Group Sepsis+MS was significantly decreased, but the expression of Nrf2, HO-1 and Occludin proteins were significantly up-regulated(P<0.05).Conclusion The mechanism of methane saline in reducing intestinal tissue injury in rats with sepsis is correlated to the activation of Nrf2/ARE pathway and the up-regulation of HO-1, thus to promote intestinal Occludin expression.