title: Peripheral injection of pancreatic polypeptide enhances colonic transit without eliciting anxiety or altering colonic secretion in rats.
abstract: Pancreatic polypeptide (PP) is a negative regulator of energy homeostasis that suppresses food intake and lowers body weight. Similar to other gastrointestinal-derived peptides, PP also modulates gastrointestinal motility and may be involved in the regulation of anxiety. Previous studies revealed that PP suppresses gastric emptying but increases colonic motility in mice. In our present study, we assessed the effect of PP on anxiety as well as colonic motility and secretory function. Intracerebroventricular and intravenous routes of PP were administered in conscious rats. Our results showed that intracerebroventricular administration of PP did not affect anxiety in the open field test. Intravenous injection of PP accelerated colonic transit, but did not significantly change fecal amount and fecal fluid composition. On the other hand, intracerebroventricular injection of PP did not alter colonic transit, fecal amount, or fluid composition. In conclusion, peripheral, but not central PP administration enhances colonic motility without eliciting anxiety or altering colonic secretion.
authors.affiliation: Department of Medical Education, Taipei Veterans General Hospital, Taipei, Taiwan.
authors.forename: Ching-Heng
authors.initials: CH
authors.lastname: Ting
authors.affiliation: Division of Digestive Medicine, Taipei City Hospital Yangming Branch, Taipei, Taiwan.
authors.forename: Ying-Chieh
authors.initials: YC
authors.lastname: Chen
authors.affiliation: Department of Anesthesiology, Tungs' Taichung MetroHarbor Hospital, Taichung, Taiwan; Department of Pharmacology, National Defense Medical Center, Taipei, Taiwan.
authors.forename: Wen-Jinn
authors.initials: WJ
authors.lastname: Liaw
authors.affiliation: Division of Gastroenterology and Hepatology, Department of Medicine, Taipei Veterans General Hospital, Taipei, Taiwan; National Yang-Ming University School of Medicine, Taipei, Taiwan.
authors.forename: Han-Chieh
authors.initials: HC
authors.lastname: Lin
authors.affiliation: Division of Gastroenterology and Hepatology, Department of Medicine, Taipei Veterans General Hospital, Taipei, Taiwan; National Yang-Ming University School of Medicine, Taipei, Taiwan. Electronic address: chency@vghtpe.gov.tw.
authors.forename: Chih-Yen
authors.initials: CY
authors.lastname: Chen
mesh_terms: D000818:Animals; D001007:Anxiety / Q000378:metabolism*; D003106:Colon / Q000187:drug effects* / Q000378:metabolism; D003346:Corticotropin-Releasing Hormone / Q000378:metabolism*; D005769:Gastrointestinal Motility / Q000187:drug effects; D007267:Injections / Q000379:methods; D051379:Mice; D010191:Pancreatic Polypeptide / Q000378:metabolism / Q000494:pharmacology*; D010446:Peptide Fragments / Q000494:pharmacology*; D010537:Peritoneum; D017207:Rats, Sprague-Dawley
chemical_list: D010446:Peptide Fragments; D010191:Pancreatic Polypeptide; D003346:Corticotropin-Releasing Hormone
keywords: Anxiety; Colon; Motility; Pancreatic polypeptide; Secretion; Transit