Pituitary adenylate cyclase activating peptide-27 – like immunoreactive nerve fibers in the mucosal layer of canine gastrointestinal tract in physiology and during inflammatory bowel disease

Changes in the density of mucosal pituitary adenylate cyclase activating peptide-27 -like immunoreactive (PACAP-27 - LI) nerve fibers within various parts of the canine gastrointestinal (GI) tract during inflammatory bowel disease (IBD) were investigated. The distribution of nerves were studied, using a single-labelling immunofluorescence technique, in the mucosal layer of canine stomach, duodenum, jejunum, and descending colon. Canine IBD caused an increase in the density of PACAP- 27-LI mucosal nerves in all studied parts of GI tract. The results suggest that PACAP in the nervous system may be involved in pathological processes during IBD.