title: Plasma hormones facilitated the hypermotility of the colon in a chronic stress rat model.
abstract: OBJECTIVE
  To study the relationship between brain-gut peptides, gastrointestinal hormones and altered motility in a rat model of repetitive water avoidance stress (WAS), which mimics the irritable bowel syndrome (IBS).
  
  
  METHODS
  Male Wistar rats were submitted daily to 1-h of water avoidance stress (WAS) or sham WAS (SWAS) for 10 consecutive days. Plasma hormones were determined using Enzyme Immunoassay Kits. Proximal colonic smooth muscle (PCSM) contractions were studied in an organ bath system. PCSM cells were isolated by enzymatic digestion and IKv and IBKca were recorded by the patch-clamp technique.
  
  
  RESULTS
  The number of fecal pellets during 1 h of acute restraint stress and the plasma hormones levels of substance P (SP), thyrotropin-releasing hormone (TRH), motilin (MTL), and cholecystokinin (CCK) in WAS rats were significantly increased compared with SWAS rats, whereas vasoactive intestinal peptide (VIP), calcitonin gene-related peptide (CGRP) and corticotropin releasing hormone (CRH) in WAS rats were not significantly changed and peptide YY (PYY) in WAS rats was significantly decreased. Likewise, the amplitudes of spontaneous contractions of PCSM in WAS rats were significantly increased comparing with SWAS rats. The plasma of WAS rats (100 µl) decreased the amplitude of spontaneous contractions of controls. The IKv and IBKCa of PCSMs were significantly decreased in WAS rats compared with SWAS rats and the plasma of WAS rats (100 µl) increased the amplitude of IKv and IBKCa in normal rats.
  
  
  CONCLUSIONS
  These results suggest that WAS leads to changes of plasma hormones levels and to disordered myogenic colonic motility in the short term, but that the colon rapidly establishes a new equilibrium to maintain the normal baseline functioning.
authors.affiliation: Department of Gastroenterology, Renmin Hospital of Wuhan University, Wuhan, China.
authors.forename: Chengbai
authors.initials: C
authors.lastname: Liang
authors.forename: Hesheng
authors.initials: H
authors.lastname: Luo
authors.forename: Ying
authors.initials: Y
authors.lastname: Liu
authors.forename: Jiwang
authors.initials: J
authors.lastname: Cao
authors.forename: Hong
authors.initials: H
authors.lastname: Xia
mesh_terms: D000818:Animals; D001921:Brain / Q000378:metabolism; D002908:Chronic Disease; D003106:Colon / Q000503:physiopathology*; D004195:Disease Models, Animal; D055724:Electrophysiological Phenomena; D005243:Feces; D005768:Gastrointestinal Hormones / Q000097:blood*; D005769:Gastrointestinal Motility / Q000502:physiology*; D008297:Male; D009119:Muscle Contraction / Q000502:physiology; D009130:Muscle, Smooth / Q000503:physiopathology; D010455:Peptides / Q000097:blood; D051381:Rats; D017208:Rats, Wistar; D013312:Stress, Physiological
chemical_list: D005768:Gastrointestinal Hormones; D010455:Peptides