title: Abdominal vagotomy dissociates the anorectic mechanisms for peripheral serotonin and cholecystokinin.
abstract: These studies compared the effects of total abdominal vagotomy (VGX) on ingestive actions produced by peripheral serotonergic and cholecystokinergic (CCKergic) stimulation in rats. Subcutaneous injection of 0.01-0.16 mumol/kg of the serotonin (5-HT) analogue 5-carboxamidotryptamine (5-CT) dose-dependently reduced mash intake equally in VGX rats and their laparotomized (LAP) controls but concurrently stimulated drinking only in the controls. The sulfated octapeptide of cholecystokinin (CCK-8, 4.0 nmol/kg ip) also reduced food intake only in the controls. In a second set of rats, vagotomy did not alter anorexia after intraperitoneal administration of either 2.0 or 8.0 mumol/kg of 5-HT or of 0.03 mumol/kg of 5-CT but abolished anorexia after a large dose of CCK-8 (8.0 nmol/kg). The completeness of vagotomy was verified histologically by immunohistochemical staining of the vagal bundles for the high molecular weight form of neurofilament-H protein. We report for the first time that 5-CT produces anorexia by a vagally independent mechanism. In contrast, 5-CT stimulates drinking by a pathway that does involve vagal function. Finally, we confirm the prediction that vagotomy dissociates the neural mechanisms for the anorectic action of peripheral 5-HTergic and CCKergic stimulation.
authors.affiliation: Department of Pharmacology, Medical College, of Pennsylvania, Eastern Pennsylvania Psychiatric Institute, Philadelphia 19129.
authors.forename: K
authors.initials: K
authors.lastname: Eberle-Wang
authors.forename: P
authors.initials: P
authors.lastname: Levitt
authors.forename: K J
authors.initials: KJ
authors.lastname: Simansky
mesh_terms: D000005:Abdomen / Q000294:innervation*; D000818:Animals; D000855:Anorexia / Q000503:physiopathology*; D002766:Cholecystokinin / Q000502:physiology*; D004305:Dose-Response Relationship, Drug; D004435:Eating / Q000187:drug effects; D008297:Male; D051381:Rats; D017207:Rats, Sprague-Dawley; D012701:Serotonin / Q000031:analogs & derivatives / Q000494:pharmacology / Q000502:physiology*; D017366:Serotonin Receptor Agonists / Q000494:pharmacology; D012844:Sincalide / Q000494:pharmacology; D013894:Thirst / Q000187:drug effects; D014628:Vagotomy
chemical_list: D017366:Serotonin Receptor Agonists; D012701:Serotonin; D002766:Cholecystokinin; C047087:5-carboxamidotryptamine; D012844:Sincalide