title: Alterations in lipid metabolism and thermogenesis with emergence of brown adipocytes in white adipose tissue in diet-induced obesity-resistant Lou/C rats.
abstract: Recent studies describe the Lou/C rat as a model of resistance to age- and diet-induced obesity and suggest a preferential channeling of nutrients toward utilization rather than storage under standard feeding conditions. The purpose of the present study was to evaluate lipid metabolism of Lou/C and Wistar rats under a high-fat (HF) diet. Four-month-old male Lou/C and Wistar animals were submitted to a 40% HF diet for 5-9 wk. Evolution of food intake, body weight, and body composition, hormonal parameters, and expression of key transcription factors and enzymes involved in lipid metabolism were determined. Wistar rats developed obesity after 5 wk of HF diet, as previously described. Among the various parameters measured, accumulation of intraperitoneal fat was particularly evident in HF-fed Wistar rats. In these animals, thermogenesis was, however, stimulated as a likely compensatory mechanism against the development of obesity. On the contrary, Lou/C animals failed to develop obesity under such a diet, and intraperitoneal fat, not including epididymal and retroperitoneal fat depots, was virtually absent. Enzyme measurements confirmed lipid utilization rather than storage, which was accompanied by the striking emergence of uncoupling protein-1, characteristic of brown adipocytes, in white adipose tissue, particularly in the subcutaneous depot.
authors.affiliation: Laboratory of Metabolism, Department of Internal Medicine, University of Geneva, Geneva, Switzerland. christelle.veyrat-durebex@unige.ch
authors.forename: Christelle
authors.initials: C
authors.lastname: Veyrat-Durebex
authors.forename: Anne-Laure
authors.initials: AL
authors.lastname: Poher
authors.forename: Aurélie
authors.initials: A
authors.lastname: Caillon
authors.forename: Xavier
authors.initials: X
authors.lastname: Montet
authors.forename: Françoise
authors.initials: F
authors.lastname: Rohner-Jeanrenaud
mesh_terms: D052437:Adipocytes, Brown / Q000502:physiology*; D052436:Adipose Tissue, White / Q000166:cytology / Q000502:physiology*; D000818:Animals; D001786:Blood Glucose / Q000378:metabolism; D015153:Blotting, Western; D002153:Calorimetry, Indirect; D004032:Diet; D004041:Dietary Fats / Q000378:metabolism / Q000494:pharmacology; D005247:Feeding Behavior / Q000187:drug effects; D015309:Glucose Clamp Technique; D005951:Glucose Tolerance Test; D007408:Intestinal Absorption / Q000235:genetics / Q000502:physiology; D050356:Lipid Metabolism / Q000502:physiology*; D008099:Liver / Q000187:drug effects / Q000378:metabolism; D008297:Male; D018482:Muscle, Skeletal / Q000187:drug effects / Q000378:metabolism; D009765:Obesity / Q000235:genetics* / Q000378:metabolism*; D012313:RNA / Q000235:genetics; D051381:Rats; D011919:Rats, Inbred Strains; D017208:Rats, Wistar; D020133:Reverse Transcriptase Polymerase Chain Reaction; D022722:Thermogenesis / Q000502:physiology*; D015430:Weight Gain / Q000187:drug effects
chemical_list: D001786:Blood Glucose; D004041:Dietary Fats; D012313:RNA