PEPTIDE-CONTAINING NEURONS REMAIN UNAFFECTED AFTER INTESTINAL AUTOTRANSPLANTATION - AN EXPERIMENTAL-STUDY IN THE PIGLET

The gut is richly supplied with peptide-containing nervous elements. I n the present immunocytochemical study the origin, occurrence and topo graphical distribution of nerves containing vasoactive intestinal poly peptide (VIP), enkephalin, substance P (SP), somatostatin, neuropeptid e Y (NPY), calcitonin gene-related peptide (CGRP), gastrin-releasing p eptide (GRP) and galanin were investigated in the porcine small intest ine. In order to study the origin (extrinsic or intrinsic) of the nerv e fibers, specimens from autotransplanted and extrinsically denervated jejunum were examined. Furthermore, possible changes in the distribut ion of intrinsic neurons after extrinsic denervation were studied. In the control jejunum each nerve fiber population had its own characteri stic topographic distribution. There was no overt difference in distri bution pattern of peptide-containing nerve fibers and cell bodies betw een the transplanted and the control segment except that NPY-, SP- and CGRP-containing nerve fibers disappeared around blood vessels. Thus V IP-, somatostatin-, GRP-, enkephalin- and galanin-containing nerve fib ers were visibly unchanged in the transplanted segment The results sup port the view that the peptide-containing nerve fibers are mainly intr insic in origin except the NPY-, SP- or CGRP-containing perivascular n erve fibers which are extrinsic to the gut wall. In addition, the resu lts of the present study suggest that transplantation and extrinsic de nervation have no major effect on the distribution pattern of the intr insic neuronal systems.