The adaptive ability of transplanted rat small intestine.

This study was performed to determine the extent to which intestinal transplants undergo functional and morphologic compensation. Animals were studied after 25 days to document how rapidly the changes occurred and after 150 days to establish whether the effects were maintained long term. Lewis isografts and Lewis Brown Norway F1 allograft recipient rats had comparable degrees of morphologic (increased bowel diameter, crypt depth, and villus height) and functional (absorption of 3H-glucose, 14C-maltose, and cyclosporine) compensation. These changes were already present by day 25 and persisted until at least day 150. The results were independent of the loss of extrinsic innervation or the intramuscular administration of cyclosporine (5 mg/kg/day). These observations support the usefulness of segmental intestinal transplantation in the treatment of surgically induced short bowel syndrome.