Role of food in appearance of growth-stimulating activity in rat proximal intestine after small-bowel resection.

The oral intake of food is important for the observed compensatory hyperplasia in the remnant small intestine after resection but the molecular events governing this response are not known. Peptides, of molecular weight 4500 and 1000 daltons, present in the the proximal intestine for 96 hr after resection and mitogenic for the intestine have been implicated in the adaptive hyperplasia. In this study, the role of food in the appearance of these peptides was assessed. The results show that after resection, rats nourished intravenously demonstrated neither a significant adaptation nor any of the detectable mucosal mitogens, whereas the rats nourished intragastrically demonstrated both hyperplasia and the mitogenic peptide(s). The association of the hyperplasia with the appearance of the mitogenic peptides in the small intestine suggests that they are important in the mechanism by which food promotes the adaptive hyperplasia.