FIGURE 8.

Administration of 1,2-NQ enhances apoptosis and proliferation of IECs along with Il11 up-regulation in the cecum of wild-type mice. Eight-week-old male mice were injected with corn oil or 1,2-NQ (2.5 or 5 mg/kg). In some experiments (A, B, C, and E), mice were injected with 1,2-NQ (5 mg/kg). Mice were sacrificed, and body weight was measured 72 h after injection. A, changes of body weight are expressed as percentages of initial body weight. Results are mean ± S.E. (error bars) (n = 8–11 mice). ***, p < 0.001 versus corn oil-treated mice. B, H&E-stained cecum sections (n = 7–11 mice). Arrowheads, apoptotic cells. Scale bar, 100 μm. C, cecum sections were stained with anti-CC3. Arrows, apoptotic cells. Scale bar, 100 μm. D, numbers of CC3-positive apoptotic cells were calculated and are expressed as numbers of CC3-positive cells per villus (n = 3–5 mice). *, p < 0.05; ns, not significant versus corn oil-treated mice. E, cecum sections were stained with anti-Ki67 and anti-cyclin D1 antibodies (n = 5 mice). Scale bar, 100 μm. F, numbers of Ki67-positive proliferating cells were calculated, and the percentage of Ki67-positive cells among total epithelial cells is expressed as the labeling index. *, p < 0.05 versus corn oil-treated mice. G, cecum RNAs were prepared, and relative amounts of Hmox1 and Il11 mRNAs were determined by qPCR. Results are means ± S.E. (n = 5 mice). *, p < 0.05; **, p < 0.01; ns, not significant versus corn oil-treated mice.