title: Gastrin-releasing peptide stimulates possum gallbladder contractility in vitro.
abstract: Reports of the action of gastrin-releasing peptide (GRP) on gallbladder contraction are limited to a few species. We compared the action of GRP, acetyl gastrin-releasing peptide 20-27 (GRP 20-27), and cholecystokinin-octapeptide (CCK-8) on gallbladder contractility with and without pretreatment with the neural inhibitor tetrodotoxin (TTX) and the bombesin antagonist [D-Phe 6, Des-Met 14]-bombesin 6-14 ethylamide (BBS 6-14 E). Full-thickness muscle strips were prepared and suspended in organ baths. The maximum GRP, GRP 20-27, and CCK-8 responses were 54.2 +/- 4.2%, 74.6 +/- 6.4%, and 69.3 +/- 6.9% of that of carbachol, respectively. Pretreatment with TTX influenced the action of GRP 20-27, and pretreatment with BBS 6-14 E influenced that of GRP and GRP 20-27. These studies show that GRP and GRP 20-27 are potent agonists of gallbladder contractility, acting via GRP-preferring receptors, and that GRP 20-27 also acts via a neural component.
authors.affiliation: Department of Surgery, Flinders Medical Centre, Bedford Park, South Australia, Australia.
authors.forename: A
authors.initials: A
authors.lastname: Carbone
authors.forename: A C
authors.initials: AC
authors.lastname: Schloithe
authors.forename: J R
authors.initials: JR
authors.lastname: Harvey
authors.forename: R A
authors.initials: RA
authors.lastname: Baker
authors.forename: G T
authors.initials: GT
authors.lastname: Saccone
mesh_terms: D000818:Animals; D001839:Bombesin / Q000031:analogs & derivatives / Q000494:pharmacology; D005260:Female; D005704:Gallbladder / Q000187:drug effects* / Q000502:physiology*; D019886:Gastrin-Releasing Peptide / Q000494:pharmacology*; D066298:In Vitro Techniques; D008297:Male; D009119:Muscle Contraction / Q000187:drug effects; D009893:Opossums; D010446:Peptide Fragments / Q000494:pharmacology; D012844:Sincalide / Q000494:pharmacology
chemical_list: D010446:Peptide Fragments; C086327:bombesin (6-14)-ethylamide, Phe(6)-des-Met(14)-; D019886:Gastrin-Releasing Peptide; D012844:Sincalide; D001839:Bombesin