title: Role of relaxin-3/RXFP3 system in stress-induced binge-like eating in female rats.
abstract: Binge eating is frequently stimulated by stress. The neuropeptide relaxin-3 (RLN3) and its native receptor RXFP3 are implicated in stress and appetitive behaviors. We investigated the dynamics of the central RLN3/RXFP3 system in a newly established model of stress-induced binge eating. Female Sprague-Dawley rats were subjected to unpredictable intermittent 1-h access to 10% sucrose. When sucrose intake stabilized, rats were assessed for consistency of higher or lower sucrose intake in response to three unpredictable episodes of foot-shock stress; and assigned as binge-like eating prone (BEP) or binge-like eating resistant (BER). BEP rats displayed elevated consumption of sucrose under non-stressful conditions (30% > BER) and an additional marked increase in sucrose intake (60% > BER) in response to stress. Conversely, sucrose intake in BER rats was unaltered by stress. Chow intake was similar in both phenotypes on 'non-stress' days, but was significantly reduced by stress in BER, but not BEP, rats. After stress, BEP, but not BER, rats displayed a significant increase in RLN3 mRNA levels in the nucleus incertus. In addition, in response to stress, BEP, but not BER, rats had increased RXFP3 mRNA levels in the paraventricular and supraoptic nuclei of the hypothalamus. Intracerebroventricular administration of a selective RXFP3 antagonist, R3(B1-22)R, blocked the stress-induced increase in sucrose intake in BEP rats and had no effect on sucrose intake in BER rats. These results provide important evidence for a role of the central RLN3/RXFP3 system in the regulation of stress-induced binge eating in rats, and have therapeutic implications for eating disorders.
authors.affiliation: Faculté de Médecine, Département de Psychiatrie et de Neurosciences, Centre de recherche de l'Institut universitaire de cardiologie et de pneumologie de Québec, Université Laval, Québec, QC, G1V 0A6, Canada.
authors.forename: Juliane
authors.initials: J
authors.lastname: Calvez
authors.affiliation: Faculté de Médecine, Département de Psychiatrie et de Neurosciences, Centre de recherche de l'Institut universitaire de cardiologie et de pneumologie de Québec, Université Laval, Québec, QC, G1V 0A6, Canada.
authors.forename: Camila
authors.initials: C
authors.lastname: de Ávila
authors.affiliation: Faculté de Médecine, Département de Psychiatrie et de Neurosciences, Centre de recherche de l'Institut universitaire de cardiologie et de pneumologie de Québec, Université Laval, Québec, QC, G1V 0A6, Canada.
authors.forename: Louis-Olivier
authors.initials: LO
authors.lastname: Matte
authors.affiliation: Faculté de Médecine, Département de Psychiatrie et de Neurosciences, Centre de recherche de l'Institut universitaire de cardiologie et de pneumologie de Québec, Université Laval, Québec, QC, G1V 0A6, Canada.
authors.forename: Geneviève
authors.initials: G
authors.lastname: Guèvremont
authors.affiliation: The Florey Institute of Neuroscience and Mental Health, Parkville, Victoria 3052, Australia; Florey Department of Neuroscience and Mental Health and Department of Anatomy and Neuroscience, The University of Melbourne, Melbourne, Victoria 3010, Australia.
authors.forename: Andrew L
authors.initials: AL
authors.lastname: Gundlach
authors.affiliation: Faculté de Médecine, Département de Psychiatrie et de Neurosciences, Centre de recherche de l'Institut universitaire de cardiologie et de pneumologie de Québec, Université Laval, Québec, QC, G1V 0A6, Canada. Electronic address: Elena.Timofeeva@fmed.ulaval.ca.
authors.forename: Elena
authors.initials: E
authors.lastname: Timofeeva
mesh_terms: D000818:Animals; D002032:Bulimia / Q000209:etiology / Q000378:metabolism*; D004435:Eating / Q000187:drug effects / Q000502:physiology*; D004597:Electroshock; D005260:Female; D007031:Hypothalamus / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D043562:Receptors, G-Protein-Coupled / Q000037:antagonists & inhibitors* / Q000235:genetics / Q000378:metabolism; D018000:Receptors, Peptide / Q000037:antagonists & inhibitors* / Q000235:genetics / Q000378:metabolism; D012065:Relaxin / Q000235:genetics / Q000378:metabolism*; D013315:Stress, Psychological / Q000150:complications / Q000378:metabolism*; D013395:Sucrose / Q000008:administration & dosage*; D065820:Zona Incerta / Q000378:metabolism
chemical_list: C577472:RXFP3 protein, rat; D043562:Receptors, G-Protein-Coupled; D018000:Receptors, Peptide; D013395:Sucrose; D012065:Relaxin
keywords: Binge eating; RXFP3; Relaxin-3; Stress; Sucrose