title: Cholecystokinin-8 increases Fos-like immunoreactivity in myenteric neurons of the duodenum and jejunum more after intraperitoneal than after intravenous injection.
abstract: The objective of this study was to measure the relative efficacy and potency of cholecystokinin-8 (CCK-8) given by intraperitoneal (i.p.) and intravenous (i.v.) injection to stimulate Fos-like immunoreactivity (Fos-LI) in neurons of the myenteric plexus in the duodenum and jejunum. The subjects for his experiment were 40 male Sprague-Dawley rats divided into eight treatment groups (n=5 rats per treatment). Four groups of rats were injected with 5, 10, and 40 microg/kg sulfated CCK-8 and saline (control) i.p., and the remaining groups with the same treatments i.v. We then detected Fos-LI, a marker for neuronal activation, in the myenteric plexus of the duodenum and jejunum, in response to the previous doses and routes. All of the CCK-8 doses administered by both routes increased Fos-LI in the myenteric plexus of the duodenum and jejunum significantly more than saline did. Although both routes were efficacious in increasing Fos-LI, CCK-8 i.p. was significantly more potent than CCK-8 i.v. These data provide immunohistochemical evidence that i.p. administration of CCK-8 is a more potent stimulant of Fos-LI in the neurons of the myenteric plexus of the duodenum and jejunum than i.v. injection.
authors.affiliation: Gastroenterology Laboratory, Department of Biomedical Sciences, College of Veterinary Medicine, Tuskegee University, Tuskegee, AL 36088, USA.
authors.forename: Tennille
authors.initials: T
authors.lastname: Webb
authors.forename: Stephen
authors.initials: S
authors.lastname: Gulley
authors.forename: Fleurette
authors.initials: F
authors.lastname: Pruitt
authors.forename: Alton R
authors.initials: AR
authors.lastname: Esdaile
authors.forename: Sanjay K
authors.initials: SK
authors.lastname: Sharma
authors.forename: James E
authors.initials: JE
authors.lastname: Cox
authors.forename: Gerard P
authors.initials: GP
authors.lastname: Smith
authors.forename: Ayman I
authors.initials: AI
authors.lastname: Sayegh
mesh_terms: D000818:Animals; D002766:Cholecystokinin / Q000008:administration & dosage*; D004305:Dose-Response Relationship, Drug; D004386:Duodenum / Q000187:drug effects / Q000276:immunology*; D007274:Injections, Intraperitoneal; D007275:Injections, Intravenous; D007583:Jejunum / Q000187:drug effects / Q000276:immunology*; D008297:Male; D009197:Myenteric Plexus / Q000187:drug effects / Q000276:immunology*; D009474:Neurons / Q000187:drug effects / Q000276:immunology*; D010446:Peptide Fragments / Q000008:administration & dosage*; D016760:Proto-Oncogene Proteins c-fos / Q000276:immunology*; D051381:Rats; D017207:Rats, Sprague-Dawley
chemical_list: D010446:Peptide Fragments; D016760:Proto-Oncogene Proteins c-fos; C410885:cholecystokinin 8; D002766:Cholecystokinin