title: Acute central effects of corticotropin-releasing factor (CRF) on energy balance: Effects of age and gender.
abstract: Previously demonstrated age-related changes in the catabolic melanocortin system that may contribute to middle-aged obesity and aging anorexia, raise the question of the potential involvement of corticotropin-releasing factor (CRF) in these phenomena, as this catabolic hypothalamic mediator acts downstream to melanocortins. Catabolic effects of CRF were shown to be mediated by both CRF1 (hypermetabolism) and CRF2 (anorexia) receptors. To test the potential role of CRF in age-related obesity and aging anorexia, we investigated acute central effects of the peptide on energy balance in male and female rats during the course of aging. Effects of an intracerebroventricular CRF injection on food intake (FI), oxygen-consumption (VO2), core- and tail skin temperatures (Tc and Ts) were studied in male and female Wistar rats of five different age-groups (from 3- to 24-month). Anorexigenic responsiveness was tested during 180-min re-feeding (FeedScale) following 24-h fasting. Thermoregulatory analysis was performed by indirect calorimetry (Oxymax) complemented by thermocouples recording Tc and Ts (indicating heat loss). CRF suppressed FI in 3-month male and female animals. In males, CRF-induced anorexia declined with aging, whereas in females it was maintained in all groups. The peptide increased VO2and Tc in all male age-groups, while the weaker hypermetabolic response characterizing 3-month females declined rapidly with aging. Thus, age-related alterations in acute central anorexigenic and hypermetabolic effects of CRF show different non-parallel patterns in males and females. Our findings underline the importance of gender differences. They also call the attention to the differential age-related changes in the CRF1 and CRF2 receptor systems.
authors.affiliation: Institute for Translational Medicine, Medical School, University of Pécs, Hungary.
authors.forename: Judit
authors.initials: J
authors.lastname: Tenk
authors.affiliation: Institute for Translational Medicine, Medical School, University of Pécs, Hungary.
authors.forename: Ildikó
authors.initials: I
authors.lastname: Rostás
authors.affiliation: Institute for Translational Medicine, Medical School, University of Pécs, Hungary.
authors.forename: Nóra
authors.initials: N
authors.lastname: Füredi
authors.affiliation: Institute for Translational Medicine, Medical School, University of Pécs, Hungary.
authors.forename: Alexandra
authors.initials: A
authors.lastname: Mikó
authors.affiliation: Institute for Translational Medicine, Medical School, University of Pécs, Hungary.
authors.forename: Szilvia
authors.initials: S
authors.lastname: Soós
authors.affiliation: Institute for Translational Medicine, Medical School, University of Pécs, Hungary.
authors.forename: Margit
authors.initials: M
authors.lastname: Solymár
authors.affiliation: Department of Anatomy, Medical School, University of Pécs, Hungary.
authors.forename: Balázs
authors.initials: B
authors.lastname: Gaszner
authors.affiliation: Institute for Translational Medicine, Medical School, University of Pécs, Hungary.
authors.forename: Miklós
authors.initials: M
authors.lastname: Székely
authors.affiliation: Institute for Translational Medicine, Medical School, University of Pécs, Hungary.
authors.forename: Erika
authors.initials: E
authors.lastname: Pétervári
authors.affiliation: Institute for Translational Medicine, Medical School, University of Pécs, Hungary. Electronic address: marta.balasko@aok.pte.hu.
authors.forename: Márta
authors.initials: M
authors.lastname: Balaskó
mesh_terms: D000367:Age Factors; D000375:Aging / Q000187:drug effects / Q000378:metabolism; D000818:Animals; D000855:Anorexia / Q000188:drug therapy / Q000378:metabolism; D003346:Corticotropin-Releasing Hormone / Q000008:administration & dosage* / Q000378:metabolism; D004435:Eating / Q000187:drug effects; D004734:Energy Metabolism / Q000187:drug effects; D005260:Female; D008297:Male; D009765:Obesity / Q000188:drug therapy / Q000378:metabolism; D010101:Oxygen Consumption / Q000187:drug effects; D010455:Peptides / Q000008:administration & dosage* / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D018019:Receptors, Corticotropin-Releasing Hormone / Q000235:genetics / Q000378:metabolism*; D012727:Sex Characteristics; D000099052:CRF Receptor, Type 1
chemical_list: C101531:CRF receptor type 2; D010455:Peptides; D018019:Receptors, Corticotropin-Releasing Hormone; D000099052:CRF Receptor, Type 1; D003346:Corticotropin-Releasing Hormone
keywords: Aging; Corticotropin-releasing factor (CRF); Energy balance; Food intake; Gender; Metabolic rate