ABSTRACT
Electrophysiologic examination of resting membrane potentials and slow wave frequencies in colonic circular smooth muscle showed no evidence for a myopathy involving Inflammatory Bowel Disease (IBD) smooth muscle. The potential importance of vasoactive intestinal peptide (VIP) in the pathophysiology of IBD is intensified by its proposed functions. In 1945, A. M. Gill proposed desiccated porcine small bowel mucosa for treatment of patients with ulcerative colitis, possibly replacing an intestinal substance. Consistent with these observations, it is believed that membrane depolarizations in canine colon are generated at the submucosal surface of circular muscle. To prepare circular muscle strips, the mucosal-submucosal layer was removed by microdissection under normal Krebs solution. In mucosa-submucosa of normal colon, VIP is present in nerve fibers in the lamina propria mucosae, the muscularis mucosae, and the submucosal plexus, and in nerve cell bodies in the submucosal plexus.
