Vascular density and <i>MMP-9</i> expression.

<p>(<b>A</b>) Colon tissues were immunostained with anti-CD31 antibody, and vessel density was determined as described in the Materials and Methods. Each value represents mean ± SD (n = 7 mice/group). *p<0.05, **p<0.01 versus day 0 mice. (<b>B</b>) MMP-9 mRNA expression in the colons of the two groups sacrificed at the indicated times was assessed by quantitative RT-PCR. Each value represents mean ± SD (n = 7 mice/group). **p<0.01 versus control mice or day 0 mice. (<b>C</b>) Immunohistochemical detection of MMP-9⁺ cells in the mouse colon tissues. The colons were removed from the AOM and DSS-treated mice at the indicated times. Immunohistochemical analysis was performed using anti-MMP-9 antibodies as described in the Materials and Methods. The cell numbers per field were counted in 5 randomly selected visual fields at 400× magnification. Values represent mean ± SD for 7 mice in each group. **p<0.01 versus day 0 mice. (<b>D</b>) Neutrophils expressing MMP-9 were detected by double-color immunofluorescence analyses using anti-Ly6G (red) and anti-MMP-9 (green) antibodies, as described in the Materials and Methods. The fluorescence images are digitally merged in the far right image. Representative results of 7 mice are shown. Original magnification, 630×.