纳米SiO_2与常规SiO_2粉尘致肺纤维化作用的研究

Comparison between the effect of pulmonary fibrosis induced by nanosized silicon dioxide and normal silicon dioxide

目的 比较纳米二氧化硅 (SiO2 )与常规SiO2 致肺纤维化的作用。方法 分别用纳米级SiO2 [粒径 (10± 5 )nm]和常规SiO2 (粒径 <5 μm)粉尘对雌性Wistar大鼠肺脏染尘 (2 0mg/只 ) ,于染尘第 3 0和 60天后处死动物 ,测定肺脏脏器系数和胶原蛋白含量 ,观察肺组织病理改变。结果 染尘后第 3 0和 60天纳米SiO2 组大鼠肺胶原蛋白含量低于常规SiO2 对照组 ,差异有显著性 (P <0 0 5或P <0 0 1) ,与生理盐水对照组相比 ,差异无显著性。病理切片观察显示 ,纳米SiO2 组大鼠肺内病变明显轻于常规SiO2 对照组。染尘后第 3 0和 60天纳米SiO2 组大鼠肺内均为细胞性结节 (Ⅰ期 ) ,常规SiO2 对照组大鼠染尘第 3 0天肺内为纤维细胞性结节 (Ⅰ +～Ⅱ +期 ) ,染尘第 60天为细胞纤维性结节 (Ⅱ +～Ⅲ期 )。纳米SiO2 组可见肺泡间隔增生及少量的胶原纤维。结论 纳米SiO2 与常规SiO2 相比致肺损伤程度较轻 ,可能与其颗粒粒径小易扩散有关。

Objective To compare the effect of pulmonary fibrosis induced by nanosized silicon dioxide (SiO 2) and with that induced by normal SiO 2.Methods Female Wistar rats were exposed to lower dose (20 mg/rat) of nanosized SiO 2 and normal SiO 2 by intratracheal injection. The rat lung/body coefficient, lung collagen and the lung pathology were investigated on 30 and 60 d after administration.Results The lung collagen in nanosized SiO 2 groups were obviously lower than that in normal SiO 2 groups (P<0.05, P<0.01) on 30 and 60 d. Pathological examination showed that pulmonary fibrosis was much milder in the nanosized SiO 2 groups than that in normal SiO 2 groups.Conclusion The effect of pulmonary damage is milder in nanosized SiO 2 than that in normal SiO 2, which may result from the diffusibility because of its ultrafine particle.