Figure 1.

Cat K mRNA is strongly upregulated in the lungs of silica-treated mice. C57BL/6 mice were instilled with PBS (control) or 2.5 mg of crystalline silica. Lungs were collected at different time intervals after instillation. (A) OH-proline lung contents. ** P < 0.01 for comparison between control and silica-treated mice. (B) Cat transcripts were quantified by RT-real-time PCR on RNA extracted from lung tissue. Results were calculated as a ratio of Cat expression to β-actin expression and expressed as percentage of controls. Values of 5 mice in each group are presented as means ± SEM. All levels of Cat expression were significantly higher in silica-treated mice compared to control mice except for Cat L (all time points), and Cat B and S (at 3 days).