烟雾吸入性肺损伤后吸入一氧化氮对早期中性粒细胞活性氧的影响

Effects of inhaled nitric oxide on ROS of polymorphonuclear leucocyte in the early stage of smoke inhalation injury

目的研究大鼠烟雾吸入性肺损伤后吸入20ppm的一氧化氮(NO)对中性粒细胞(PMN)活性氧的影响。方法72只雄性Wistar大鼠,体重为250～350g,随机分入Ⅰ、Ⅱ及Ⅲ组,每组各24只。各组再按伤后6、12及24小时3个时相点均分为3组。另取8只大鼠以同样方法致烟雾性损伤,测定伤后1小时伤后值。再取另外8只非致伤大鼠测定伤前值。除了伤前值组大鼠外,其余各组均复制成重度烟雾吸入性损伤模型。Ⅰ、Ⅱ及Ⅲ3组分别于致伤后2小时开始应用动物呼吸机进行定容机械通气,Ⅰ组吸入空气,Ⅱ组吸入氧气(FiO2=0．4),Ⅲ组除吸氧外(FiO2=0．4)再吸入20ppm NO。处死大鼠后制备肺组织匀浆。用试剂盒测定肺组织活性氧水平(ROS)及肿瘤坏死因子α(TNF-α)含量。数据均采用SPSS10．0统计软件包进行完全随机设计方差分析,结果用x±s表示。结果伤后肺组织匀浆ROS含量均升高。伤后6小时及12小时时,3组之间无显著性差异(P<0．05)。至24小时,Ⅱ组较Ⅰ组降低(P<0．05),Ⅲ组较Ⅰ组降低更为明显(P<0．01),Ⅲ组亦低于Ⅱ组(P<0．05)。TNF-α含量伤后明显升高,伤后12小时及24小时,Ⅲ组均低于Ⅱ组(P<0．05)。ROS与TNF-α含量正相关性明显(r=0．442,P<0．01)。结论吸入浓度为20ppm的NO能抑制烟雾吸入性损伤大鼠的PMN产生ROS。

Objective To investigate the effects of inhaled 20 ppm NO on reactive oxygen species （ ROS） of polymorphonuclear （ PMN ） leucocyte in rat lung in early stage of smoke inhalation injury. Methods Seventy-two healthy male Wistar rats,weighting 250-350gm,were divided into three groups randomly, named group one, group two and group three. Each group,containing 24 rats,and was again divided into three subgroups randomly according to three different intervals of 6h, 12h and 24h after injury. Another 8 rats constituted the postinjury group. Still another 8 rats,free from any injury,constituted pre-injury group and were used to establish normal values. All the rats except those in pre-injury group were subjected to smoke inhalation injury. Two hours following smoke exposure,constant volume ventilation was undergone in group one,group two and group three respectively with the aid of animal ventilator. Rats in group one,air was administered,in group two oxygen（ FiO2 =0.4） was administered and in group three NO gas was administered continuously at a concentration of 20 ppm besides oxygen （ FiO2 = 0.4 ）. Right lung were homogenated. ROS and TNF-α were measured by the test kits. Analysis of variance （ ANOVA ） was permormed for statistical analysis with aid of SPSS 10.0 software. Data were expressed as mean ± standard error of the mean. Results The content of ROS increased after injury. There was no difference among the three groups at 6 and 12 h after injury （ P 〉 0. 05 ）. At 24 h after injury, it was lower in group two than that in group one （ P 〈 0.05 ） , and it was significantly lower in group three than that in group one（ P 〈0.01 ）. In addition, it was also lower in group three than that in group two（P 〈0.05）. The content of TNF-α increased significantly. At 12 h and 24 h,it was significantly lower in group three than that in group two（ P 〈 0.05 ）. Higher degree of positive correlation couldbe found between the ROS and TNF-α （ r = 0. 442, P 〈 0.01 ）. Conclusion ROS production of PMN is inhibited after 20ppm NO inhaled in rats in the egrlystage of smoke inhalation injury.