Epithelial cell proliferation and intestinal absorptive function during starvation and refeeding in the rat.

1. Intestinal epithelial cell production and intestinal absorption were measured in fed, starved and refed rats. 2. Four days' starvation significantly decreased the crypt cell production rate (CCPR), absorption, small intestinal length and crypt cell population. 3. There was an immediate increase in absorption 1 day after refeeding, which preceded a slower increase in CCPR. The absorption rate then decreased progressively after refeeding, and was significantly lower than control levels 1 week after refeeding. The CCPR, however, increased more gradually, reaching control levels after 2 days and then 'overshooting' control values. 4. There was no significant change in the crypt cell population immediately after refeeding; thus we propose that the initial increase in absorption on refeeding is either due to an accelerated maturation rate of the enterocytes or to the migration of enterocytes from the base of the villus to the functional zone. 5. The rapid recruitment of absorptive function appeared to be a 'one-off' event, the villus compartment then having to wait for increased cell production in the crypts to repopulate the villi.