Abstract: | In fasted rats, single injection of pentagastrin (250 mug/kg) stimulates epithelial cell proliferation in the duodenum and colon, but not in the esophagus. Fasting for 64 hours suppresses cell proliferation more markedly in colonic crypts than in duodenal crypts, and pentagastrin restores the cell proliferative activity of the colon and duodenum to levels comparable with those of fed rats. In both duodenal and colonic crypts, differentiating-proliferative cells in the mid-portion of the crypts are more responsive to pentagastrin stimulation than immature proliferative cells at the base of the crypts. Non-dividing epithelial cells are not affected. Pentagastrin has no influence on cell proliferation in fed rats. |