Negishi T
Biology Department, Abiko Research Laboratory, Central Research Institute of Electric Power Industry, Chiba, Japan.
Exp Anim. 1995 Apr;44(2):131-8. doi: 10.1538/expanim.44.131.
Male golden hamsters were exposed to coal fly ash (FA) at the concentration of 0 (control), 1, 2, or 20 mg/m3 for 3 or 6 months (20 hr/day, 7 days/week). They were sacrificed at 0, 1, 3 and 6 months after exposure to undergo morphological investigation of the lung clearance of particles ingested by alveolar macrophages (AMs) following excessive deposition of FA particles. Particle-laden AMs in a cluster decreased in inverse proportion to the dust burden after the cessation of exposure. AMs with well-spread lamellipodia frequently appeared on the degenerated AMs in a cluster. In addition, neutrophils also agglomerated mainly in the alveoli proximal to the terminal bronchioles and ingested a small amount of particles. These results suggest that AMs and neutrophils might recruit into alveoli enclosing AMs in necrosis and reingest released particles. Macrophages in bronchioles generally ingested fewer particles than those clustered in alveoli. This finding suggests that AMs ingesting a small amount of released particles could move on the mucociliary escalator of the terminal bronchioles. On the other hand, AMs ingesting a large amount of particles would agglomerate in alveoli due to the loss of their migrating ability. The latter agglomeration of particle-laden AMs might be responsible for the retardation of lung clearance in proportion to the lung burden of particles.
将雄性金黄仓鼠暴露于浓度为0（对照）、1、2或20毫克/立方米的煤粉煤灰（FA）中3或6个月（每天20小时，每周7天）。在暴露后0、1、3和6个月时将它们处死，以对FA颗粒过度沉积后肺泡巨噬细胞（AM）摄取的颗粒在肺内的清除情况进行形态学研究。暴露停止后，聚集成簇的载有颗粒的AM数量与粉尘负荷呈反比减少。在成簇的退化AM上经常出现具有广泛伸展的片状伪足的AM。此外，中性粒细胞也主要聚集在终末细支气管近端的肺泡中，并摄取少量颗粒。这些结果表明，AM和中性粒细胞可能会募集到包围坏死AM的肺泡中，并重新摄取释放的颗粒。细支气管中的巨噬细胞通常比聚集在肺泡中的巨噬细胞摄取的颗粒少。这一发现表明，摄取少量释放颗粒的AM可以在终末细支气管的黏液纤毛输送系统上移动。另一方面，摄取大量颗粒的AM由于其迁移能力丧失而会在肺泡中聚集。载有颗粒的AM的后一种聚集可能是导致肺清除延迟与肺内颗粒负荷成比例的原因。
