Figure 2

Upregulation of expression of γH2AX and αSMA after 3, 6, and 12 wk of silica inhalation. (A) Representative image of γH2AX positive cells (green), and (B) αSMA expression (brown) in lung tissue at 16 hr after a 3, 6, and 12 wk silica inhalation exposure (15 mg/m3, 6 h/d, 5 d/wk). The scale bar denotes 20 µm. Rats exposed to filtered air served as the controls; n = 5.