Corticosterone treatment inhibits cell proliferation in the gastric epithelium of suckling rats.

During the 3rd postnatal week, the rat gastrointestinal tract undergoes major changes which depend on the different factors such as dietary transition and hormones. Glucocorticoids are closely involved in these processes, yet a clear proliferative response to these agents in the gastric epithelium has not yet been established. The aim of this study was to determine the effect of corticosterone on cell proliferation in the gastric mucosa of suckling rats. We also measured plasma corticosterone concentration in fed and fasted suckling (18-day-old) and weaning rats (22-day-old) observing that fasting increased the levels in animals of both ages (P < 0.05). Cell kinetic parameters, i.e., metaphase index, cell production rate, and potential doubling time, were obtained by vincristine blockade in control and corticosterone-treated 18-day-old pups. The metaphase index was strongly inhibited by corticosterone (P < 0.001), as was the cell production rate (P < 0.05), indicating a high potential doubling time in treated rats. Mucosal and glandular thickness were also measured, but no differences between treated and untreated animals were found. The results suggest that corticosterone treatment has an inhibitory effect on cell proliferation in the gastric mucosa in suckling rats, and that the high endogenous levels observed during fasting do not affect the proliferative activity.