title: Effects of obestatin on energy balance and growth hormone secretion in rodents.
abstract: Ghrelin stimulates food intake and adiposity and thereby increases body weight (BW) in rodents after central as well as peripheral administration. Recently, it was discovered that the gene precursor of ghrelin encoded another secreted and bioactive peptide named obestatin. First reports appeared to demonstrate that this peptide requires an amidation for its biological activity and acts through the orphan receptor, GPR-39. Obestatin was shown to have actions opposite to ghrelin on food intake, BW, and gastric emptying. In the present study, we failed to observe any effect of obestatin on food intake, BW, body composition, energy expenditure, locomotor activity, respiratory quotient, or hypothalamic neuropeptides involved in energy balance regulation. In agreement with the first report, we were unable to find any effect of obestatin on GH secretion in vivo. Moreover, we were unable to find mRNA expression of GPR-39, the putative obestatin receptor, in the hypothalamus of rats. Therefore, the results presented here do not support a role of the obestatin/GPR-39 system in the regulation of energy balance.
authors.affiliation: Department of Pharmacology, German Institute of Human Nutrition, Potsdam-Rehbruecke, Germany.
authors.forename: Rubén
authors.initials: R
authors.lastname: Nogueiras
authors.forename: Paul
authors.initials: P
authors.lastname: Pfluger
authors.forename: Sulay
authors.initials: S
authors.lastname: Tovar
authors.forename: Myrtha
authors.initials: M
authors.lastname: Arnold
authors.forename: Sharon
authors.initials: S
authors.lastname: Mitchell
authors.forename: Amanda
authors.initials: A
authors.lastname: Morris
authors.forename: Diego
authors.initials: D
authors.lastname: Perez-Tilve
authors.forename: Maria J
authors.initials: MJ
authors.lastname: Vázquez
authors.forename: Petra
authors.initials: P
authors.lastname: Wiedmer
authors.forename: Tamara R
authors.initials: TR
authors.lastname: Castañeda
authors.forename: Richard
authors.initials: R
authors.lastname: DiMarchi
authors.forename: Matthias
authors.initials: M
authors.lastname: Tschöp
authors.forename: Annette
authors.initials: A
authors.lastname: Schurmann
authors.forename: Hans-Georg
authors.initials: HG
authors.lastname: Joost
authors.forename: Lynda M
authors.initials: LM
authors.lastname: Williams
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Langhans
authors.forename: Carlos
authors.initials: C
authors.lastname: Diéguez
mesh_terms: D000818:Animals; D004435:Eating / Q000187:drug effects / Q000502:physiology; D004734:Energy Metabolism / Q000187:drug effects* / Q000502:physiology; D015870:Gene Expression / Q000187:drug effects / Q000502:physiology; D054439:Ghrelin; D013006:Growth Hormone / Q000378:metabolism*; D007031:Hypothalamus / Q000187:drug effects* / Q000378:metabolism / Q000502:physiology; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D036361:Peptide Hormones / Q000378:metabolism / Q000494:pharmacology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D043562:Receptors, G-Protein-Coupled / Q000235:genetics / Q000378:metabolism; D014628:Vagotomy; D015430:Weight Gain / Q000187:drug effects / Q000502:physiology
chemical_list: C512928:GPR39 protein, mouse; D054439:Ghrelin; D036361:Peptide Hormones; D043562:Receptors, G-Protein-Coupled; C512328:obestatin, mouse; D013006:Growth Hormone