Leptin receptor-deficient obese Zucker rats reduce their food intake in response to hypobaric hypoxia.

Abstract : Exposure to hypoxia induces anorexia in humans and rodents, but the role of leptin remains under discussion and that of orexigenic and anorexigenic hypothalamic neuropeptides remains unknown. The present study was designed to address this issue by using obese (Lepr(fa)/Lepr(fa)) Zucker rats, a rat model of genetic leptin receptor deficiency. Homozygous lean (Lepr(FA)/Lepr(FA)) and obese (Lepr(fa)/Lepr(fa)) rats were randomly assigned to two groups, either kept at ambient pressure or exposed to hypobaric hypoxia for 1, 2, or 4 days (barometric pressure, 505 hPa). Food intake and body weight were recorded throughout the experiment. The expression of leptin and vascular endothelial growth factor (VEGF) genes was studied in adipose tissue with real-time quantitative PCR and that of selected orexigenic and anorexigenic neuropeptides was measured in the hypothalamus. Lean and obese rats exhibited a similar hypophagia (38 and 67% of initial values at day 1, respectively, P < 0.01) and initial decrease in body weight during hypoxia exposure. Hypoxia led to increased plasma leptin levels only in obese rats. This resulted from increased leptin gene expression in adipose tissue in response to hypoxia, in association with enhanced VEGF gene expression. Increased hypothalamic neuropeptide Y levels in lean rats 2 days after hypoxia exposure contributed to accounting for the enhanced food consumption. No significant changes occurred in the expression of other hypothalamic neuropeptides involved in the control of food intake. This study demonstrates unequivocally that altitude-induced anorexia cannot be ascribed to anorectic signals triggered by enhanced leptin production or alterations of hypothalamic neuropeptides involved in anabolic or catabolic pathways.
Type de document :
Article dans une revue
AJP - Endocrinology and Metabolism, American Physiological Society, 2006, 290 (3), pp.E591-7. 〈10.1152/ajpendo.00289.2005〉
Liste complète des métadonnées

Littérature citée [53 références]  Voir  Masquer  Télécharger

http://www.hal.inserm.fr/inserm-00410553
Contributeur : Valérie Sinniger <>
Soumis le : jeudi 10 septembre 2009 - 17:31:06
Dernière modification le : jeudi 11 janvier 2018 - 02:37:15
Document(s) archivé(s) le : samedi 26 novembre 2016 - 11:21:47

Fichier

 Accès restreint
Fichier visible le : jamais

Connectez-vous pour demander l'accès au fichier

Identifiants

Collections

SSA | U836

Citation

Nadine Simler, Alexandra Grosfeld, André Peinnequin, Michèle Guerre-Millo, André-Xavier Bigard. Leptin receptor-deficient obese Zucker rats reduce their food intake in response to hypobaric hypoxia.. AJP - Endocrinology and Metabolism, American Physiological Society, 2006, 290 (3), pp.E591-7. 〈10.1152/ajpendo.00289.2005〉. 〈inserm-00410553〉

Partager

Métriques

Consultations de la notice

175