Immunohistochemistry for α-SMA, and TGF-β in the lung tissues following treatment with ZnONP at 150 cm2
/rat. (A - D), α-SMA in the lungs. (A) vehicle control at 24 h; (B) ZnONP at 24 h; (C) ZnONP at 1 wk; (D) ZnONP at 4 wks. Note that α-SMA positive cells (dark brown staining) were seen in smooth muscle layer of airways and vessels of normal lung (A and B). In addition, they were seen profusely in the fibrotic lesions (arrow) at 1 (C) and 4 wks (D) after ZnONP instillation. (E - H), TGF-β in the lungs. (E) vehicle control at 24 h; (F) ZnONP at 24 h; (G) ZnONP at 1 wk; (H) ZnONP at 4 wks. Note that 'I' denotes the area of TGF-β positive fibrosis and the whole image of (H) was dominated by TGF-β positivity.