大气混合污染物对大鼠肺组织CC16及细胞因子的影响

目的测定大气污染物对大鼠肺组织CC16、TNF-α和IL-6的mRNA表达影响。方法用日本产低流量PM10空气采样器采集PM10颗粒物,采样滤膜用生理盐水超声震荡洗脱,混悬液定容为15mg/ml。48只体重为200~240g Wistar大鼠随机分为3个实验组和1个对照组。实验组大鼠分别气管注入15mg/ml PM10的生理盐水混悬液1ml,对照组大鼠注入1ml生理盐水。次日,实验组大鼠静态吸入浓度分别为15、12、400mg/m3的SO2、NO2、CO空气混合气,每天吸入2h,对照组吸入正常空气。于吸入气体污染物1天、7天和30天后次日分别处死实验组和对照组大鼠,取肺组织,采用RT-PCR方法测定TNF-α、IL-6和CC16的mRNA表达水平;采用免疫组化和Western blotting测定肺和BALF中CC16的水平。结果吸入大气污染物组在吸入后1天和7天其肺组织CC16 mRNA的表达量明显低于对照组;细胞因子TNF-α和IL-6 mRNA表达增强,高于对照组,并于染毒初期即染毒第1天和第7天增高明显,染毒第30天,又呈下降趋势。免疫组化检测显示,实验组大鼠肺组织CC16表达水平在染毒后1天,7天时显著高于对照组,而在30天时低于对照组。BALF中CC16表现为1天和7天时显著低于对照和30天组。结论大气污染物作用于大鼠呼吸系统后,大鼠肺组织和BALFCC16表达量下降,TNF-α和IL-6 mRNA表达增强,并且在污染物作用早期变化明显。

Effects of air mixed certain pollutants on the expression of CC16 and certain cytokine in pulmonary tissue of rats

OBJECTIVE: To determine mRNA expressions of CC16, TNF-alpha and IL-6 in pulmonary tissue of rats exposed to air mixed pollutants and to explore mechanism of air pollutants on lung damage. METHODS: 48 Wistar rats were randomly divided into control group and three pollutant exposure groups. Pollutant exposure rats were intratracheally instillated contenting 15mg PM10 1ml physiological saline suspension and control group rats were intratracheally instillated 1ml physiological saline solution. Next day, three pollutant exposure groups rats were statically inhaled with mixed SO2 (15mg/m3), NO2 (12mg/m3), CO (400mg/m3) for 2h per day, and control group rats were inhaled with normal air. The expressions in pulmonary tissue of CC16, TNF-alpha and IL-6 mRNA were separately examined by RT-PCR, and the levels of CC16 in lung tissues and bronchoalveolar lavage fluids (BALF) were respectively measured by Immunohistochemistry and Western blotting after inhalation of mixed pollutants at the days of 1,7, and 30. RESULTS: In rats inhaled with mixed pollutants, CC16 mRNA expressions of lung tissues significantly decreased at the days of 1, 7, and significantly increased at the days of 30. TNF-alpha and IL-6 mRNA expressions of lung tissues in rats inhaled with mixed pollutants at the days of 1, 7 were more higher than those of control groups. At the days of 30, TNF-alpha and IL-6 mRNA expressions of lung tissues decreased again. Immunohistochemistry results showed that CC16 expressions in lung tissues were significantly higher than those of control groups at the days of 1, 7, and significantly decreased at the days of 30. The levels of CC16 in BALF at the days of 1, 7 were lower than those of control groups and at the days of 30. CONCLUSION: The expression levels of CC16 in lung tissues and BALF could decrease and TNF-alpha and IL-6 expressions could increase of lung tissues in rats inhaled with mixed pollutants at early stage of exposure pollutants.