title: Gastrointestinal hormone receptors on isolated smooth muscle cells from gastric antrum of the rabbit.
abstract: The regulation by gastrointestinal polypeptide hormones of contraction and relaxation of functionally isolated smooth muscle cells from gastric antrum of the rabbit has been investigated. Gastrin, cholecystokinin (CCK-8) and motilin induced a rapid contraction of isolated cells: significant response occurred within a 5-sec incubation with these peptides and maximal response (40% decrease in cell length) after 30 sec. A higher sensitivity of smooth muscle cells to gastrin and CCK-8 than to motilin stimulations was demonstrated (EC50 = 10 pM for both gastrin and CCK-8 and EC50 = 1 nM for motilin). The minimal gastrin fragment required to get full contraction was the C-terminal pentapeptide amide common to gastrin and CCK. Proglumide inhibited gastrin- or CCK-8- but not motilin-induced contractions with an IC50 of 50 microM. contraction induced by gastrin and motilin required normal levels of extracellular calcium, whereas that due to CCK-8 seemed to be independent of extracellular calcium. Vasoactive intestinal polypeptide (VIP) caused a relaxation of smooth muscle cells maximally contracted by carbachol or CCK-8 or gastrin (EC50 = 2.2 nM) with a parallel increase in intracellular cAMP content.
authors.affiliation: Laboratoire de Biochimie des Membranes, CNRS UPR-41 INSERM U-249, Faculté de Pharmacie, Montpellier, France.
authors.forename: C
authors.initials: C
authors.lastname: Moummi
authors.forename: R
authors.initials: R
authors.lastname: Magous
authors.forename: J P
authors.initials: JP
authors.lastname: Bali
mesh_terms: D000818:Animals; D002118:Calcium / Q000502:physiology; D002766:Cholecystokinin / Q000037:antagonists & inhibitors / Q000378:metabolism* / Q000502:physiology; D005755:Gastrins / Q000378:metabolism* / Q000502:physiology; D066298:In Vitro Techniques; D009037:Motilin / Q000378:metabolism* / Q000502:physiology; D009119:Muscle Contraction; D009130:Muscle, Smooth / Q000378:metabolism* / Q000502:physiology; D011377:Proglumide / Q000494:pharmacology; D011706:Pyloric Antrum / Q000166:cytology / Q000378:metabolism; D011817:Rabbits; D011956:Receptors, Cell Surface / Q000378:metabolism; D014660:Vasoactive Intestinal Peptide / Q000502:physiology
chemical_list: D005755:Gastrins; D011956:Receptors, Cell Surface; D014660:Vasoactive Intestinal Peptide; D009037:Motilin; D002766:Cholecystokinin; D011377:Proglumide; D002118:Calcium