Figure 5

Histopathological images of nanoparticle inhaled rat model (20×). (a) Normal terminal bronchi and alveoli structures; (b) At 30 min post-IT injections, the charcoal particles attached to and/or absorbed (arrow heads) by the bronchial epithelium, alveolar epithelium and residual macrophages; (c) At 120 min post-IT injections, the charcoal particles distributed in cytoplasm of macrophages, type II alveolar epithelial cells and bronchial epithelial cells (arrow heads). The alveolar type I epithelial cells are cuboidal and hyperplastic. Most of the type II alveolar cells had numerous intracytoplasmic nanoparticles and hypertophic