Role of relaxin-3/RXFP3 system in stress-induced binge-like eating in female rats. (March 2016)

• Record Type: Journal Article
• Authors: Calvez, Juliane; de Ávila, Camila; Matte, Louis-Olivier; Guèvremont, Geneviève; Gundlach, Andrew L.; Timofeeva, Elena
• Is Part Of: Neuropharmacology. Volume 102(2016)
• Page Start: 207
• Page End: 215
• Publication Date: 2016-03
• Subjects: Binge eating -- Stress -- Sucrose -- Relaxin-3 -- RXFP3; BEP binge-like eating prone -- BER binge-like eating resistant -- BSTov oval subnucleus of the bed nucleus of the stria terminalis -- CeA central nucleus of amygdala -- CRF corticotropin releasing factor -- CSF cerebrospinal fluid -- PD postnatal days -- MeA medial nucleus of amygdala -- NI nucleus incertus -- NIc pars compacta of the NI -- NId pars dissipata of the NI -- OD optical density -- PVN paraventricular hypothalamic nucleus -- PVNm magnocellular part of the PVN -- PVNp parvocellular part of the PVN -- RLN3 relaxin-3 -- RXFP3 relaxin family peptide receptor 3 -- SD Sprague–Dawley -- SE standard error -- SON supraoptic nucleus; Neuropsychopharmacology -- Periodicals; Autonomic Agents -- Periodicals; Neuropsychopharmacologie -- Périodiques; Neuropsychopharmacology; Periodicals; Electronic journals; 615.78
• DOI: 10.1016/j.neuropharm.2015.11.014
• Languages: English
• ISSNs: 0028-3908

Abstract

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. Graphical abstract: Highlights: We developed a model of binge-like eating prone (BEP) and binge-like eating resistant (BER) rats. BEP rats displayed elevated consumption of sucrose under non-stressful conditions (30% > BER). Stress induced additional marked increase in sucrose intake (60% > BER) in BEP rats. Expression of relaxin-3 and its receptor RXFP3 was increased by stress in BEP rats. RXFP3 antagonist blocked stress-induced increase in sucrose intake in BEP rats.