目的探讨锡冶炼生产性粉尘能否致SD大鼠肺损伤，为锡尘肺诊断提供重要的确诊证据。方法选择SPF级成年SD大鼠44只，随机分为锡精炼车间粉尘组、锡粗炼车间粉尘组、标准石英粉尘阳性对照组和生理盐水阴性对照组，每组9～13只，分别于染尘后180 d和270 d处死大鼠，称量各组大鼠肺湿重，并计算肺脏器系数；观察各组大鼠染尘后肺组织病理形态学变化。结果大鼠染锡粉尘180 d，镜下观察可见两肺部分细小支气管和肺泡周围有折光性强的粉尘颗粒沉着，呈散在尘灶/细胞结节和炎性肉芽肿分布；肺组织纤维化程度为Ⅰ～Ⅲ级；染尘第270天时大鼠两肺呈灰黑色，镜下可见在肺内细小支气管周围有散在的粉尘颗粒沉着，并可见少量尘灶/细胞结节和炎性肉芽肿形成，结节内可见少量纤维组织增生和少量胶原纤维形成，个别尘灶表现为明显的纤维性结节，VG染色结果呈阳性，纤维化程度仍为Ⅰ～Ⅲ级。染尘后第270天锡精炼车间粉尘组大鼠肺脏器系数高于阴性对照组（ P＜0．05），但低于阳性对照组（ P＜0．05）。结论锡冶炼生产性粉尘可致SD大鼠染尘后产生特异性肺损伤，即肺组织出现肉芽肿病变和尘灶结节内纤维组织增生，符合锡冶炼工尘肺特异性病理变化的诊断标准。%Objective To explored whether specific lesions of tin pneumoconiosis in the lung tissue injury of SD rats induced by tin smelting industrial dust , and to provide references for the diagnosis of tin pneumoconiosis . Methods Forty-four SPF-level SD rats were randomly divided into tin dust group in smelting workshop ,tin dust group in tin refining workshop,positive control group of standard quartz dust ,negative control group of saline ,9-13 rats in each group .The rats were killed in batches after 180-and 270-day exposure to tin dust .The ratio of pulmonary wet weight to dry weight ( W/D) was measured while the coefficient of the lung was calculated .The pathomorphological changes of rats′lungs were observed in each group .Results After the rats were exposed to tin dust for 180 days, some yellow dust particles of strong refractivity were observed around small bronchi and alveolar tube in the tissues of both lungs by microscope with sporadic distribution of dust focal ,fiber cell nodules and inflammatory granuloma .The pathological grades of pulmonary fibrosis ranged from grade Ⅰto grade Ⅲ.After being exposed to tin dust for 270 days,both lungs of the rats showed ashy black ,the scattered dust particles were observed around small bronchi in the lung tissues by microscope with a few dust focal ,fiber cell nodules and inflammatory granuloma ,a few fibrous tissues were proliferated while a few collagen fibers were observed in the nodules ,some individual dust foci seemed to be fi-brous nodules obviously .The result of VG staining was positive with the pathological grades of pulmonary fibrosis ranged from gradeⅠto gradeⅢ.After 270-day exposure to tin dust ,the coefficient of the lung in the tin dust group in smelting workshop was higher than that in the negative control group ( P<0 .05 ) but lower than that in the positive control group (P<0.05).Conclusion Tin smelting industrial dust may lead to specific lung tissue injury in SD rats after being exposed to tin dust ,which shows granuloma formation in the lung tissues as well as fibrous tissues prolifera -ted in the dust focal nodules .It meets the diagnostic criteria for specific pathological changes in tin smelting workers with pneumoconiosis .
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