title: Cholecystokinin-8 activates myenteric neurons in 21- and 35-day old but not 4- and 14-day old rats.
abstract: Cholecystokinin (CCK) activates the myenteric neurons of adult rats. The goal of this work is to determine the ontogeny of this activation by CCK-8 in the myenteric plexus of the duodenum (2cm immediately following the pyloric sphincter aborally) and compare it with that of the dorsal vagal complex (DVC) - which occurs in 1-day old pups. Despite the existence of both of the CCK receptors, CCK(1) and CCK(2), in 4, 14, 21 and 35 day old rats, CCK-8 (0, 5, 10, 20 and 40μg/kg, i.p.) increased Fos-like immunoreactivity (Fos-LI, a marker for neuronal activation) in the myenteric neurons of 21- and 35-day old rats but in the DVC of all age groups. As such, this belated activation of myenteric neurons by CCK-8 compared to the DVC may reflect a delayed role for these neurons in CCK-related functions.
authors.affiliation: Department of Biomedical Sciences, Tuskegee University, Tuskegee, AL, USA.
authors.forename: Martha C
authors.initials: MC
authors.lastname: Washington
authors.forename: Candace R
authors.initials: CR
authors.lastname: Murry
authors.forename: Shannon J
authors.initials: SJ
authors.lastname: Raboin
authors.forename: Allison E
authors.initials: AE
authors.lastname: Roberson
authors.forename: Mahmoud M
authors.initials: MM
authors.lastname: Mansour
authors.forename: Carol S
authors.initials: CS
authors.lastname: Williams
authors.forename: Ayman I
authors.initials: AI
authors.lastname: Sayegh
mesh_terms: D000367:Age Factors; D000818:Animals; D000831:Animals, Newborn; D002452:Cell Count; D048429:Cell Size; D002766:Cholecystokinin / Q000494:pharmacology*; D004386:Duodenum / Q000187:drug effects / Q000254:growth & development* / Q000294:innervation* / Q000378:metabolism; D005260:Female; D015870:Gene Expression / Q000235:genetics; D008297:Male; D009197:Myenteric Plexus / Q000166:cytology / Q000187:drug effects / Q000254:growth & development* / Q000378:metabolism; D009474:Neurons / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D016761:Oncogene Proteins v-fos / Q000378:metabolism; D010446:Peptide Fragments / Q000494:pharmacology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D043886:Receptor, Cholecystokinin A / Q000235:genetics; D043887:Receptor, Cholecystokinin B / Q000235:genetics; D017552:Solitary Nucleus / Q000187:drug effects / Q000378:metabolism; D014630:Vagus Nerve / Q000187:drug effects / Q000378:metabolism
chemical_list: D016761:Oncogene Proteins v-fos; D010446:Peptide Fragments; D043886:Receptor, Cholecystokinin A; D043887:Receptor, Cholecystokinin B; C410885:cholecystokinin 8; D002766:Cholecystokinin