蔺草染土尘致大鼠肺部病变的实验研究

Study on the pulmonary fibrogenetic effect induced by rush-mat dust in rats

目的 研究蔺草染土粉尘的致尘肺作用。方法 SD雄性大鼠以非暴露式气管内染尘(5 0mg/只 ) ,于染尘后 3、6、12个月 ,取大鼠肺和肺淋巴结作病理和电镜观察 ,测定肺组织胶原蛋白和血清铜蓝蛋白 (CP)含量。结果 染尘后 12个月 ,蔺草染土尘组大鼠肺湿重 (2 .6 9± 0 .2 2 )g ,高于对照组 [(1.87± 0 .2 5 )g]和TiO2 组 [(2 .2 5± 0 .2 6 )g],但低于SiO2 组 [(11.4 1± 1.6 3)g];蔺草染土尘组大鼠肺干重 (0 .4 7± 0 .0 3)g ,高于对照组 [(0 .32± 0 .0 3)g]和TiO2 组 [(0 .4 1± 0 .0 8)g],但低于SiO2 组 [(2 .0 6± 0 .2 8)g];蔺草染土尘组大鼠肺胶原蛋白含量 [(10 3.0 8± 14 .79)mg]高于对照组 [(75 .96± 13.91)mg]和TiO2 组 [(85 .84± 17.6 2 )mg],但低于SiO2 组 [(497.5 0± 10 0 .80 )mg];蔺草染土尘组大鼠血清CP含量为 (18.0 3± 1.87)U/L ,高于对照组 [(15 .0 5± 2 .2 4 )U/L]和TiO2 组 [(16 .92± 1.6 7)U/L],但低于SiO2组 [(2 5 .37± 3.5 8)U/L]。以上各指标各组间的差异均有显著性 (P <0 .0 5或P <0 .0 1)。蔺草染土尘组大鼠病理观察可见肺巨噬细胞肺泡炎、Ⅱ型肺泡上皮细胞增多及肺泡间隔增宽 ,有 1～ 2级矽结节和少量胶原纤维性变。电镜下可见 。

Objective To investigate the fibrogenetic effects induced by rush-mat dust in rats. Methods SD rats were treated with 50 mg of rush-mat dust per rat by intra-tracheal instillation,sacrificed 3,6,and 12 months respectively after exposure.The lung tissue and lung limph-node were taken out for pathological and electron microscopic examination.The content of collagen and ceruloplasmin(CP) in lung tissues were also determined. Results After treatment for 12 months,fresh wet lung weight in rush-mat dust group[(2.69±0.22)g] was higher than those in saline group [(1.87 ±0.25)g],TiO_2 group[(2.25±0.26)g],but lower than that in SiO_2 group[(11.41±1.63)g];dry lung weight in rush-mat dust group[(0.47±0.03)g] was higher than those in saline group[(0.32±0.03)g],TiO_2 group[(0.41±0.08)g],but lower than that in SiO_2 group[(2.06±0.28)g] ;lung collagen content in rush-mat dust group[(103.08±14.79)mg] was higher than those in saline group [(75.96 ± 13.91)mg ,TiO_2 group[(85.84±17.62)mg],but lower than that in SiO_2 group[(497.50±100.80)mg];CP content in rush-mat dust group[(18.03±1.87)U/L]was higher than those in saline group[(15.05± 2.24) U/L],TiO_2 group[(16.92±1.67)U/L],but lower than that in SiO_2 group [(25.37 ±3.58)U/L], P < 0.05 or P < 0.01 .Pathological examination showed lung macrophage alveolitis,broadening of alveolar interval,one to two grade of silicotic nodes and increased amount of type Ⅱ epithelial cell in alveola as well as slight collagenous fibrosis in lung tissue of rush-mat dust group.Under electron microscope,primary and secondary lysosome and medullary sheath-like phagocytic residual body were found in lung tissue of rush-mat dust group,meanwhile the amount of type Ⅱ alveolar epithelial cell and collagen fiber were slightly increased but these changes were less than those of quartz group. Conclusion The rush-mat dusts have slight pulmonary fibrogenetic effect on rat.