Changes in cell proliferation and differentiation of adult rat small intestine epithelium after adrenalectomy - kinetic, biochemical, and morphological studies

The effects of 10-day bilateral adrenalectomy on morphometry, proliferation , and apoptosis were determined in the small intestine of 3-month-old Sprag ue-Dawley rats. The activities of sucrase, lactase, and its respective mRNA , aminopeptidase N, and intestinal alkaline phosphatase were also evaluated . Adrenalectomy lead to partial atrophy and disorganization of the epitheli um, with an increased number of goblet and Paneth cells and a reduction of crypt cell proliferation paralleled by a marked increase in villus apoptosi s. Biochemical assays revealed that aminopeptidase N and intestinal alkalin e phosphatase activities were significantly decreased, whereas disaccharida ses were increased by adrenalectomy. The corresponding induction of lactase mRNA suggests an active response of the epithelium. In conclusion, adrenal ectomy modified maturation and the differentiation processes of the small i ntestinal mucosa, especially in the proximal part of the small intestine. T his result points: to an important role of adrenals and glucocorticoids in the trophic status of the adult small intestinal mucosa.