摘要目的 评价富氢液对大鼠内毒素性急性肺损伤时Toll样受体4(TLR4)/髓样分化因子88(MyD88)信号通路的影响.方法 清洁级健康雄性SD大鼠40只,3月龄,体重250～ 300 g,采用随机数字表法分为4组(n=10):对照组(C组)、急性肺损伤组(ALI组)、富氢液组(H组)和急性肺损伤+富氢液组(ALI+H组).采用气管内滴注脂多糖5 mg/kg的方法制备大鼠内毒素性急性肺损伤模型.滴注后1和6h时,H组和ALI+H组腹腔注射0.6 mmol/L富氢液10 ml/kg,其余2组腹腔注射等容量生理盐水.滴注后12h时,收集支气管肺泡灌洗液(BALF),采用ELISA法检测TNF-α、IL-1β和IL-6的浓度;随后处死大鼠取肺,观察病理学结果,行肺损伤评分;称重,计算肺湿重/干重(W/D)比值;采用Western blot法检测TLR4、MyD88和NF-κB的表达.结果 与C组比较,ALI组和ALI+H组BALF TNF-α、IL-1β和IL-6的浓度、肺损伤评分及肺W/D比值升高,肺TLR4、MyD88和NF-κB的表达上调(P＜0.05);与ALI组比较,ALI+H组BALF TNF-α、IL-1β和IL-6的浓度、肺损伤评分及肺W/D比值降低,肺TLR4、MyD88、NF-κB的表达下调(P＜0.05).结论 富氢液可通过抑制肺组织TLR4/MyD88信号通路减轻大鼠内毒素性急性肺损伤.

abstractsObjective To evaluate the effects of hydrogen-rich saline on Toll-like receptor 4 (TLR4)/myeloid differentiation factor 88 (MyD88) pathway in rats with endotoxin-induced acute lung injury (ALI).Methods Forty pathogen-free male Sprague-Dawley rats,aged 3 months,weighing 250-300 g,were randomly divided into 4 groups (n =10 each) using a random number table:control group (group C);ALI group;hydrogen-rich saline group (group H);ALI + hydrogen-rich saline group (ALI + H group).ALI was induced by intratracheal instillation of lipopolysaccharide (LPS) 5 mg/kg.At 1 and 6 h after LPS instillation,0.6 mmol/L hydrogen-rich saline 10 ml/kg was injected intraperitoneally in H2 and ALI + H2 groups,while the equal volume of normal saline was given in the other two groups.At 12 h after LPS instillation,bronchoalveolar lavage fluid (BALF) was collected for determination of the concentrations of tumor necrosis factor-alpha (TNF-α),interleukin-1beta (IL-1β) and IL-6 by enzyme-linked immunosorbent assay.The animals were then sacrificed,and lungs were removed for examination of the pathological changes which were scored and for determination of wet to dry lung weight ratio (W/D ratio),and expression of TLR4,MyD88 and nuclear factor kappa B (NF-κB) (by Western blot).Results Compared with group C,the concentrations of TNF-α,IL-1β and IL-6 in BALF,lung injury score and W/D ratio were significantly increased,and the expression of TLR4,MyD88 and NF-κB was up-regulated in ALI and ALl + Hgroups (P＜0.05).Compared with group ALI,the concentrations of TNF-α,IL-1β and IL-6 in BALF,lung injury score and W/D ratio were significantly decreased,and the expression of TLR4,MyD88 and NF-κB was down-regulated in ALI + H group (P＜0.05).Conclusion Hydrogen-rich saline can reduce endotoxin-induced ALI through inhibiting TLR4/MyD88 signaling pathway in the lung tissues of rats.