title: Correlation between colonic secretion and colonic motility in rats: Role of ghrelin.
abstract: OBJECTIVE
  To explore the relationship between colonic secretory function and colonic motility.
  
  
  METHODS
  Using a rat model chronically implanted with intracerebroventricular (ICV) and cecal catheters, we validated the correlation between colonic secretion and colonic motor functions, as well as the role of ICV injection volume.
  
  
  RESULTS
  Compared to saline controls (5 μL/rat), ICV acyl ghrelin at 1 nmol/5 μL enhanced the total fecal weight, accelerated the colonic transit time, and increased the fecal pellet output during the first hour post-injection, while ICV des-acyl ghrelin at 1 nmol/5 μL only accelerated the colonic transit time. These stimulatory effects on colonic motility and/or secretion from acyl ghrelin and des-acyl ghrelin disappeared when the ICV injection volume increased to 10 μL compared with saline controls (10 μL/rat). Additionally, the ICV injection of 10 μL of saline significantly shortened the colonic transit time compared with the ICV injection of 5 μL of saline. The total fecal weight during the first hour post-injection correlated with the colonic transit time and fecal pellet output after the ICV injection of acyl ghrelin (1 nmol/5 μL), whereas the total fecal weight during the first hour post-injection correlated with the fecal pellet output but not the colonic transit time after the ICV injection of des-acyl ghrelin (1 nmol/5 μL).
  
  
  CONCLUSIONS
  Colonic secretion does not always correlate with colonic motility in response to different colonic stimulations. Acyl ghrelin stimulates colonic secretion.
authors.affiliation: Hsien-Hao Huang, Institute of Clinical Medicine, National Yang-Ming University School of Medicine, Taipei 112, Taiwan.
authors.forename: Hsien-Hao
authors.initials: HH
authors.lastname: Huang
authors.affiliation: Hsien-Hao Huang, Institute of Clinical Medicine, National Yang-Ming University School of Medicine, Taipei 112, Taiwan.
authors.forename: Ching-Heng
authors.initials: CH
authors.lastname: Ting
authors.affiliation: Hsien-Hao Huang, Institute of Clinical Medicine, National Yang-Ming University School of Medicine, Taipei 112, Taiwan.
authors.forename: Yu-Fong
authors.initials: YF
authors.lastname: Syu
authors.affiliation: Hsien-Hao Huang, Institute of Clinical Medicine, National Yang-Ming University School of Medicine, Taipei 112, Taiwan.
authors.forename: Shi-Chuan
authors.initials: SC
authors.lastname: Chang
authors.affiliation: Hsien-Hao Huang, Institute of Clinical Medicine, National Yang-Ming University School of Medicine, Taipei 112, Taiwan.
authors.forename: Chih-Yen
authors.initials: CY
authors.lastname: Chen
mesh_terms: D000818:Animals; D002552:Cerebral Ventricles; D003106:Colon / Q000187:drug effects* / Q000378:metabolism; D005769:Gastrointestinal Motility / Q000187:drug effects*; D005772:Gastrointestinal Transit / Q000187:drug effects; D054439:Ghrelin / Q000494:pharmacology*; D008297:Male; D051381:Rats; D017207:Rats, Sprague-Dawley
chemical_list: D054439:Ghrelin; C422650:ghrelin, des-n-octanoyl
keywords: Colonic transit time; Fecal pellet output; Ghrelin; Intracerebroventricular injection; Secretion; Transit