烟碱对腹腔感染败血症小鼠的保护作用及其机制研究

Protective effect of nicotine against septicemia in mice after cecal ligation and puncture

摘要:

目的 探讨烟碱激活胆碱能抗炎通路对败血症的保护作用及其机制。方法 采用盲肠结扎并穿 孔（CLP）法复制败血症模型。65 只健康昆明小鼠分为对照组、CLP 组和烟碱400μg/kg 组，记录CLP 后 24、36 和48 h 的生存率。另取18 只小鼠分组同上，CLP 后20 h 计算肺湿干重比、败血症严重程度评分，行 肝、肺组织病理学检查。另取120 只小鼠随机分为对照组、CLP 组，以及烟碱400、200 和40μg/kg 组，酶 联免疫吸附法检测CLP 后1、2、4 和6 h 血浆TNF-α 和IL-1β 的浓度。结果 术后24、36 和48 h，烟 碱400μg/kg 组生存率较CLP 组升高（P <0.05）；术后20 h 烟碱400μg/kg 组肺湿干重比和败血症严重程 度评分较CLP 组降低（P <0.05），肝、肺组织病理改变较CLP 组减轻。术后2、4 和6 h，烟碱400、200 和 40μg/kg 组血浆TNF-α 浓度较CLP 组降低（P <0.05）；术后1 和6 h，烟碱400、200 和40μg/kg 组血 浆IL-1β 浓度较CLP 组降低（P <0.05）。烟碱400μg/kg 组血浆TNF-α 浓度在术后2 h 低于40μg/kg 组 （P <0.05），术后6 h 低于200 和40μg/kg 组（P <0.05）。并术后2 和4 h 烟碱200μg/kg 组血浆TNF-α 浓 度较40μg/kg 组降低（P <0.05）。术后4 h 烟碱400μg/kg 组血浆IL-1β 浓度低于200 和40μg/kg 组（P <0.05）。 结论 烟碱减轻腹腔严重感染小鼠败血症严重程度，改善肝、肺的病理组织学变化，降低机体促炎症细胞因子 水平，提高生存率。

Abstract:

Objective To investigate whether nicotine, a nicotinic acetylcholine receptor (nAChR) agonist, has protective effect on septicemia. Methods A septicemia model was induced by cecal ligation and puncture (CLP). Totally 65 female mice were randomly divided into 3 groups. The control group (15 mice) received sham operation, the CLP group (20 mice) received cecal ligation and puncture (CLP), and the mice in nicotine group (30 mice) were intraperitoneally injected with 400 μg/kg nicotine 30 min before CLP. The survival rates were recorded 24, 36 and 48 h after CLP. Additional 18 female mice were grouped according to the same method as above; at the 20th h after operation, the septicemia severity score and the lung wet/dry weight ratio were evaluated and the liver and the lungs were histopathologically examined. Still 120 more female mice were randomly divided into 5 groups, i.e. control group, CLP group, nicotine 400 μg/kg group, nicotine 200 μg/kg group and nicotine 40 μg/kg group. The mice were sacrificed at the 1st, 2nd, 4th and 6th h after CLP. The plasma concentrations of proinflammatory cytokines including tumor necrosis factor alpha (TNF-α) and interleukine 1 beta (IL-1β) were measured using ELISA. Results At the 24th, 36th and 48th h after CLP, the survival rate of the nicotine 400 μg/kg group was significantly higher than that of the CLP group (P < 0.05). At the 20th h after CLP, the septicemia severity score and the lung wet/dry weight ratio significantly decreased in the nicotine 400 μg/kg group compared with the CLP group (P < 0.05), the pathological changes of the liver and the lungs were ameliorated compared to the CLP group. At the 2nd, 4th and 6th h after CLP, the plasma levels of TNF-α in the the nicotine 400, 200 and 40 μg/kg groups were lower than those of the CLP group (P < 0.05). The plasma level of TNF-α in the the nicotine 400 μg/kg group was lower than that of the nicotine 40 μg/kg group 2 h after CLP (P < 0.05), and lower than those of the nicotine 200 and 40 μg/kg groups 6 h after CLP (P < 0.05). The plasma level of TNF-α in the the nicotine 200 μg/kg group was lower than that of the nicotine 40 μg/kg group 2 and 4 h after CLP (P < 0.05). At the 1st and 6th h after CLP, the plasma IL-1β levels of the nicotine 400, 200 and 40 μg/kg groups were lower than that of the CLP group (P < 0.05). At the 4th h aftr CLP, the plasma IL-1β level of the nicotine 400 μg/kg group was lower than those of the nicotine 200 and 40 μg/kg groups (P < 0.05). Conclusions Nicotine has protective effects against septicemia in mice through activation of the cholinergic anti-inflammatory pathway to inhibit production of inflammatory cytokines.