被动吸烟对大鼠肺组织Clara细胞及CC16的影响

Effect of Passive Smoking on Clara Cell and CC16 in Rat Lung Tissue

目的研究被动吸烟不同时间大鼠肺组织Clara细胞及其分泌蛋白CC16的变化,以探讨被动吸烟与肺部慢性炎症性疾病发生的关系。方法将Wistar雄性大鼠随机分为被动吸烟1、2、3月组和正常对照组,每组10只。进行HE染色,观察实验组大鼠肺组织光镜表现,以透射电镜观察其Clara细胞的超微结构。以RT-PCR法检测各组大鼠肺组织CC16mRNA的表达水平,以免疫组织化学法检测肺组织Clara细胞数量,以酶联免疫吸附法检测支气管肺泡灌洗液(BALF)中CC16含量。结果被动吸烟3月组大鼠终末细支管上皮Clara细胞超微结构有显著改变;HE染色见肺泡壁变薄,相互融合成肺大泡。随着被动吸烟时间的延长,大鼠肺组织CC16mRNA的表达、Clara细胞的数量及BALF中CC16的含量逐渐降低。被动吸烟2月和3月组大鼠肺组织CC16mRNA的表达、Clara细胞的数量及BALF中CC16的含量与正常对照组比较,差异有统计学意义(P均<0.01)。被动吸烟1月组大鼠肺组织CC16mRNA的表达、Clara细胞的数量及BALF中CC16的含量与对照组比较,差异无统计学意义(P>0.05)。结论在一定吸烟量条件下,随暴露时间延长,Clara细胞数量及CC16的合成及分泌量减少,这可能与肺部慢性炎症性疾病的发生发展有一定的关系。

Objective To observe the effect of passive smoking on Clara cells and secretion of Clara cell secretory protein (CC16) in rat lung tissue and to find some relations between passive smoking and chronic inflammation in the lung. Methods 40 male rats were randomly divided into 4 groups: passive smoking for 1 month (group 1), 2 months (group 2), and 3 months (group 3) and control group (n=10). The change of Clara cell ultrastructure was detected through transmission electron microscope and the lung pathology was examined by HE stain. The expression of CC16 mRNA in the lung was detected by RT-PCR. The number of Clara cells and synthesis of CC16 were detected by immunohistochemistry, the CC16 level in BALF was detected by ELISA. Results The ultrastructure of Clara cells in group 3 was destroyed greatly and the formation of pneumatocele was observed. The percentage of Clara cells in terminal bronchioles in group 2 and group 3 significantly decreased than that of the control(P<0.01). The level of CC16 in BALF in group 2 and group 3 significantly decreased (P<0.01), the expression of CC16 mRNA in the lung in group 2 and group 3 was significantly down regulated compared with the control (P<0.01). The level of CC16 mRNA, Clara cells and CC16 in BALF in group 1 did not show a significant difference compared with the control. Conclusion In a certain level, the longer the term of smoking, the less the number of Clara cells and the secretion of CC16 are. The occurrence and development of chronic inflammation in lung is associated with the level of cigarette smoking and the term of smoking.