DISTRIBUTION OF VIP-IMMUNOREACTIVE NERVE-CELLS AND FIBERS IN THE HUMAN ILEOCECAL REGION

VIP-containing nerve cells and fibers in the human ileocecal region (p re-junctional ileum, ileocecal and cecocolonic junctions, post-junctio nal cecum and colon) have been evaluated by immunocytochemistry. A hig h density of VIP-positive neurons and nerve fibers was found in all la yers of the ileum. At all colonic levels examined and at both junction s, the percentage of VIP-containing cells was higher in the submucous plexus than in the myenteric plexus. At both junctions, the muscle wal l was devoid of, and the myenteric plexus extremely poor in VIP-positi ve nerve fibers and cells. These data suggest that motility of these j unctions is not - or only to a minor extent - regulated in man by VIP- containing nerves, at variance with other gut sphincteric areas.