金属研磨尘染毒大鼠支气管肺泡灌洗液的变化

目的　观察金属研磨的混合粉尘对大鼠呼吸系统的损伤作用。方法　大鼠经支气管注入磨工粉尘染尘后饲养 2周 ,采用大鼠支气管肺灌洗技术 ,分析灌洗液中细胞含量、分类、存活率及乳酸脱氢酶 (LDH)、碱性磷酸酶 (ALP)活力的变化。结果　染尘大鼠肺泡灌洗液中细胞含量随磨工粉尘染尘剂量的加大而增大 ,且均高于SiO2 尘组。大鼠支气管肺泡灌洗液中性粒细胞比例 [SiO2 粉尘组为 (33 .83± 4 .54) % ,1 0、2 5、50mg/ml磨工粉尘组分别为 (2 6 .50± 3 .99) %、(36 .0 0± 3 .58) %和 (38.0 0±2 .1 0 ) % ]均较对照组 [(2 .83± 0 .75) % ]明显增加 ;巨噬细胞比例 [SiO2 粉尘组为 (62 .1 7± 4 .54) % ,1 0、2 5、50mg/ml磨工粉尘组分别为 (70 .83± 3 .66) %、(60 .83± 2 .1 4 ) %和 (58.1 7± 2 .48) % ]比对照组[(95 .67± 1 .2 1 ) % ]相应降低 ,差异均有显著性 (P <0 .0 1 )。对照组大鼠肺泡灌洗液细胞存活率达80 %以上 ,与磨工粉尘组、TiO2 组的差异有显著性 (P <0 .0 1 )。各染尘组大鼠肺灌洗上清液中LDH、ALP活力明显增加 ,与对照组的差异有显著性 (P <0 .0 1或P <0 .0 5) ,随磨工粉尘染尘剂量加大 ,LDH、ALP活力逐渐升高。结论　磨工粉尘对大鼠肺细胞有损害作用 ,进一步证实磨工粉尘可能对肺脏有致纤

Changes in bronchoalveolar lavage fluid of rats exposed to metal grinding dusts

OBJECTIVE: To investigate the effects of composite grinding dusts on rat respiratory system. METHODS: Rats were administrated with grinding dusts by intratracheal injection. After 2 weeks, the total numbers of cells, the percentage of differential cell, the survival rate of cell, and the activity of lactate dehydrogenase(LDH) and alkaline phosphatase(ALP) in bronchoalveolar lavage fluid were analyzed. RESULTS: Along with increasing concentration of grinding dusts, the total number of cells in lavage also increased, and was more than that in quartz group. Compared with control group, the percentage of neutrophil in lavage of rats treated with grinding dust and quartz significantly increased and meanwhile that of macrophage significantly decreased[PMN: quartz group (33.83 +/- 4.54)%; grinding dusts group (26.50 +/- 3.99)%, (36.00 +/- 3.58)%, (38.00 +/- 2.10)% at 10, 25, 50 mg/ml respectively. Macrophages: quartz group (62.17 +/- 4.54)%; grinding dusts group (70.83 +/- 3.66)%, (60.83 +/- 2.14)%, (58.17 +/- 2.48)%] while those in control group were (2.83 +/- 0.75)%, (95.67 +/- 1.21)% respectively. The cell survival rate in lavage in control group was 80%, but that in grinding dust and TiO2 group significantly decreased(P < 0.01). The activity of LDH and ALP in all rats treated with dusts obviously increased, and there was significant difference compared with control group(P < 0.01 or P < 0.05). Furthermore, there was significant difference between grinding dust group and quartz group, and between grinding dust group and TiO2 group respectively. CONCLUSION: Metal grinding dust is very harmful to rat's lung cells and may cause fibrogenesis in the lungs.