High dose PGE
administration drives epithelial cell proliferation in the setting of chronic colitis. A. Immunohistochemical staining of incorporated BrdU. Cells under S-phase (proliferative) are labeled with BrdU as brown nuclei. Original magnification 200 ×, Bars indicate 100 μm. B Proliferative index (Number of BrdU positive cells per crypt) was counted in intestinal epithelial cells. BrdU positive cells were counted in 10 crypts of each colon segment per high power field (HPF) (30 crypts/mouse). The high dose group (n = 8) has significantly greater number of BrdU positive cells per crypt than PBS treated controls (n = 7). Data are expressed as mean (± SD) (*P < 0.05).