Bronchoalveolar lavage (BAL) analysis 24 h, 1 wk, and 4 wks after instillation of ZnONP to rats. (A - G), cytological analysis of BAL after instillation of ZnONP at 50 and 150 cm2/rat. (A), number of total cells; (B), number of PMN; (C), number of eosinophils. Representative BAL cell images of vehicle control (D) and ZnONP instillation (150 cm2) at 24 h (E), 1 wk (F), and 4 wks (G). Black arrows indicate alveolar macrophages; blue arrows indicate PMN; red arrows indicate eosinophils; green arrows indicate giant cells. (H and I), levels of total protein (H) and LDH (I) in the BAL from rats treated with ZnONP. Levels of LDH in BAL expressed as fold-change compared to vehicle control. (J - M), expression of inflammatory mediators in the BAL from rats instilled with ZnONP. (J), IL-1β; (K), eotaxin; (L), IL-13; (M), TGF-β. Values are mean ± S.D. n = 6 for 24 h and 4 wks groups and n = 4 for 1 wk groups. Significance versus vehicle control (VEH): * p < 0.05, ** p < 0.01, # p < 0.001.