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目的 分析染矽尘大鼠早期不同时间点、以及不同染尘量支气管肺泡灌洗液(BALF)中硝酸盐/亚硝酸盐(NO2-/NO3-)、硝化酪氨酸(NT)的含量变化以及与病理变化之间的关系,探讨一氧化氮代谢产物作为矽肺早期炎性标志物的可能性.方法 将Wistar大鼠随机分为对照组、15、30、60 mg/mL染矽尘实验组,每组42只.一次性气管内注入染尘,染尘后1、3、7、14、21、28 d每组分别处死7只大鼠,收集BALF,酶联免疫吸附法(ELISA)测定BALF中硝化酪氨酸,硝酸酶还原法测定NO2-/NO3-,对肺组织标本进行HE染色行病理学观察.结果 在染尘后1～28 d内,各染尘组大鼠BALF中NO2-/NO3-水平明显高于对照组,差异均有统计学意义(P＜0.05);各染尘组NO2-/NO3-水平在1d就开始增高,并在第14 d时达到高峰,随后又有所下降.观察期内,大部分时间点染尘组大鼠BALF中硝化酪氨酸水平明显高于对照组(P＜0.05),各染尘组硝化酪氨酸水平较对照组明显增加,并在第14 d时达到高峰.结论 NO2-/NO3-作为矽肺早期炎性标志物具有一定的可行性.“,”Objective To evaluate Nitrogen Monoxide metabolites (NO2-/NO3-and nitrotyrosine) as indicators of early silicosis for association with pulmonary pathological findings of silica-exposed rats in acute inflammatory stage.Methods Wistar male rats were randomly divided into control group and three experimental groups (dose of dust 15,30,60 mg/ml),each group with 42 rats.Rats in the control group were treated with 1 ml normal saline by trachea instillation,whereas the rats in experimental groups were exposed to 1 nd silica suspension by one-time trachea instillation.Seven rats of each group were sacrificed after exposed to silica on the 1 th,3 th,7 th,14 th,21 th,28 th day,then bronchoalveolar lavage fluid (BALF)was collected.The concentrations of NO2-/NO3-and nitrotyrosine in the BALF were detected with ELISA and nitrate reduction method.Pulmonary pathological findings of the four groups were observed under light microscope as well.One-way ANOVA analyses and Pearson correlation test were used for statistical analysis.Results The concentrations of NO2-/NO3-in BALF among silica-exposed groups were significantly higher than that of the control group (P ＜ 0.05).The NO2-/NO3-levels detected increased immediately on the 1 st day,reaching the peak on the 14 th day and decreased in later days after silicaexposure.NO2-/NO3-increased time was good synchronous with the inflammatory reaction process of silicosis,as well as NO2-/NO3-levels and stained dust dose had a better dose-response relationship.The levels of nitrotyrosine among silica-exposed groups were significantly higher compared with control group (P ＜ 0.05).There was no obvious relationship between the nitrotyrosine concentrations in BALF and exposure dose.Conclusion Nitrogen Monoxide metabolites NO2-/NO3-can be considered as an indicators of early silicosis.