VIP is involved in peripheral CRF-induced stimulation of propulsive colonic motor function and diarrhea in male rats

摘要

We investigated whether vasoactive intestinal peptide (VIP) and/or prosta-glandins contribute to peripheral corticotropin-releasing factor (CRF)-induced CRF receptor-mediated stimulation of colonic motor function and diarrhea in rats. The VIP antagonist, 4C1-D-Phefi, Leul7VIP injected intraperitoneally completely prevented CRF (10 xg/kg ip)-induced fecal output and diarrhea occurring within the first hour after injection, whereas pretreatmenl with the prostaglandins synthesis inhibitor, indomethacin, had no effect. In submucosal plexus neurons, CRF induced significant c-Fos expression most prominently in the terminal ileum compared with duodenum and jejunum, whereas no c-Fos was observed in the proximal colon. c-Fos expression in ileal submucosa was colocalized in 93.4 of VIP-positive neurons and 31.1 of non-VIP-labeled neurons.