title: Involvement of cholecystokinin 2 receptor in food intake regulation: hyperphagia and increased fat deposition in cholecystokinin 2 receptor-deficient mice.
abstract: The role of cholecystokinin (CCK) as a satiety factor has been extensively documented. Although most work implies that CCK1 receptor mediates the control of food intake, a contributing role for CCK2 receptor (CCK2R) in the CCK-induced satiety cannot be totally excluded. The hypothesis that CCK2R invalidation disrupts regulatory pathways with impact on feeding behavior was examined in CCK2R(-/-) mice. CCK2R(-/-) mice developed obesity that was associated with hyperphagia. Obesity was related with increased fat deposition resulting from adipocyte hypertrophy. Expression of several adipokines was dysregulated consistently with obesity. Moreover, obesity was associated with disturbed glucose homeostasis as revealed by increased fasting glycemia and insulinemia, impaired glucose tolerance, and hepatic insulin resistance in CCK2R(-/-) mice. In vitro analysis of isolated adipocytes metabolism was consistent with increased storage but preserved insulin sensitivity. Suppression of feeding and concomitant increased expression of hypothalamic proopiomelanocortin after intracerebroventricular injection of gastrin into control mice demonstrates that hypothalamic CCK2 receptors mediate inhibition of food intake. Comparative analysis of hypothalamic mediator gene expression in fed knockout and control mice demonstrated overexpression of ghrelin receptors in CCK2R(-/-) mice, indicating up-regulation of orexigenic pathways. This effect was also observed after body weight normalization, indicating a causative role in the development of hyperphagia and obesity of CCK2R(-/-) mice. Our results give evidence that CCK2 receptor activity plays a contributing regulatory role in the control of food intake.
authors.affiliation: Institut National de la Santé et de la Recherche Médicale Unit 531, Institut Fédératif de Recherche 31, Université de Toulouse 3, 31432 Toulouse Cedex 4, France.
authors.forename: Pascal
authors.initials: P
authors.lastname: Clerc
authors.forename: Maria Gràcia
authors.initials: MG
authors.lastname: Coll Constans
authors.forename: Hubert
authors.initials: H
authors.lastname: Lulka
authors.forename: Stéphanie
authors.initials: S
authors.lastname: Broussaud
authors.forename: Charlotte
authors.initials: C
authors.lastname: Guigné
authors.forename: Stéphane
authors.initials: S
authors.lastname: Leung-Theung-Long
authors.forename: Christophe
authors.initials: C
authors.lastname: Perrin
authors.forename: Claude
authors.initials: C
authors.lastname: Knauf
authors.forename: Christian
authors.initials: C
authors.lastname: Carpéné
authors.forename: Luc
authors.initials: L
authors.lastname: Pénicaud
authors.forename: Catherine
authors.initials: C
authors.lastname: Seva
authors.forename: Rémy
authors.initials: R
authors.lastname: Burcelin
authors.forename: Philippe
authors.initials: P
authors.lastname: Valet
authors.forename: Daniel
authors.initials: D
authors.lastname: Fourmy
authors.forename: Marlène
authors.initials: M
authors.lastname: Dufresne
mesh_terms: D050154:Adiposity; D000818:Animals; D001069:Appetite Regulation / Q000235:genetics*; D001786:Blood Glucose / Q000032:analysis / Q000378:metabolism; D001835:Body Weight; D004734:Energy Metabolism; D005951:Glucose Tolerance Test; D006963:Hyperphagia / Q000235:genetics*; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D008820:Mice, Obese; D009043:Motor Activity; D009765:Obesity / Q000235:genetics*; D043887:Receptor, Cholecystokinin B / Q000235:genetics* / Q000502:physiology*
chemical_list: D001786:Blood Glucose; D043887:Receptor, Cholecystokinin B