title: Three weeks of postweaning exercise in DIO rats produces prolonged increases in central leptin sensitivity and signaling.
abstract: In rats selectively bred to develop diet-induced obesity (DIO) 3 wk of postweaning exercise reduces weight and adipose regain for 10 wk after exercise cessation, despite intake of 31% fat high-energy (HE) diet. To test the hypothesis that this effect is due to increased central leptin sensitivity, 4-wk-old DIO rats were fed the HE diet and left sedentary (Sed), exercised for 3 wk, and then remained sedentary for 10 additional weeks (Ex/Sed) or continued exercise for a full 13 wk (Ex). After 3 wk, leptin (5 mg/kg ip) induced a 36% decrease in 24-h food intake in Ex rats, while Sed rats had no change in 24-h intake. Ex rats also had 23% more leptin-induced phospho-STAT3 (pSTAT3)-expressing neurons in the arcuate nucleus (ARC) and 95% and 68% higher (125)I-labeled leptin receptor binding in the ventromedial and dorsomedial nuclei than did Sed rats, respectively. At 7 wk after onset, leptin decreased 24-h intake by 20% in Ex and 24% in Ex/Sed rats without altering Sed intake. After a total of 13 wk, compared with Sed rats, Ex and Ex/Sed rats had 58% and 38% less fat, respectively, but leptin failed to decrease food intake in any group. Nevertheless, Ex, but not Ex/Sed rats, still had 32% more ARC leptin-induced pSTAT3-expressing neurons than Sed rats. These data suggest that brief postweaning exercise in DIO rats that are inherently leptin resistant causes a sustained resistance to obesity on HE diet, which is, in part, due to increased central leptin sensitivity.
authors.affiliation: Neurology Service (127C VA Medical Center, 385 Tremont Ave., E. Orange, NJ 07018-1095, USA.
authors.forename: Christa M
authors.initials: CM
authors.lastname: Patterson
authors.forename: Sebastien G
authors.initials: SG
authors.lastname: Bouret
authors.forename: Ambrose A
authors.initials: AA
authors.lastname: Dunn-Meynell
authors.forename: Barry E
authors.initials: BE
authors.lastname: Levin
mesh_terms: D000273:Adipose Tissue / Q000502:physiology; D000818:Animals; D001111:Arcuate Nucleus of Hypothalamus / Q000502:physiology; D001786:Blood Glucose / Q000378:metabolism; D001833:Body Temperature Regulation / Q000502:physiology; D031204:Caloric Restriction; D004032:Diet; D004435:Eating / Q000502:physiology; D048049:Extracellular Signal-Regulated MAP Kinases / Q000096:biosynthesis; D007150:Immunohistochemistry; D007328:Insulin / Q000097:blood; D020738:Leptin / Q000097:blood / Q000502:physiology*; D008297:Male; D009765:Obesity / Q000503:physiopathology*; D010286:Paraventricular Hypothalamic Nucleus / Q000502:physiology; D010805:Physical Conditioning, Animal / Q000502:physiology*; D051381:Rats; D050796:STAT3 Transcription Factor / Q000235:genetics / Q000502:physiology; D015398:Signal Transduction / Q000502:physiology*; D013686:Telemetry; D015430:Weight Gain / Q000502:physiology; D000521:alpha-MSH / Q000378:metabolism
chemical_list: D001786:Blood Glucose; D007328:Insulin; D020738:Leptin; D050796:STAT3 Transcription Factor; C494088:Stat3 protein, rat; D000521:alpha-MSH; D048049:Extracellular Signal-Regulated MAP Kinases