Non-hormonal regulation of intestinal adaptation.

Infusion of simple sugars and some amino acids into the lumen of the small bowel stimulates local mucosal growth where these substrates come into direct contact with the mucosa. This stimulation does not require active absorption or mucosal metabolism of the substrate and in the case of glucose can be inhibited by phlorizin. Infusion of sugars and some amino acids into ileal lumen results in mucosal growth of proximal bowel distant from the site of infusion. Diverting pancreatico-biliary secretions from proximal to distal small bowel lumen markedly stimulates growth in distal small bowel, while the absence of these secretions from the duodenojejunum paradoxically results in growth of the mucosa at this site. Such regional differences in adaptation suggest that regulation of mucosal growth is different in proximal and distal small bowel.