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- Title
Exercise Modulates AMP Kinase Activity in Hypothalamus of Wistar Rats.
- Authors
Fernandes, Maria Fernanda A.; Flores, Marcelo; Ropelle, Eduardo R.; Ueno, Mirian; Velloso, Lício; Saad, Mario; Carvalheira, Jose B.
- Abstract
AMP-activated protein kinase (AMPK) and mTOR are key regulators of cellular energy balance and of the effects of leptin on food intake. Acute exercise is associated with increase sensitivity to the effects of leptin on food intake in an IL-6 dependent manner. To determine whether exercise modulates the AMPK and mTOR response to leptin in hypothalamus in an IL-6 dependent manner, the animals performed two 3-h exercise bouts, separated by one 45-min rest period. Intracerebroventricular IL-6 infusion reduced food intake and pretreatment with AMPK activators and mTOR inhibitors prevented IL-6-induced anorexia. Activators of AMPK increased food intake in control rats to a greater extent than that observed in exercised ones, whereas inhibitors of AMPK had the opposite effect. Exercise was associated with both reduced phosphorylation of AMPK/ACC signaling pathway and increased phosphorylation of proteins involved in mTOR signal transduction in hypothalamus. The regulatory role of IL-6 in mediating the modulation in AMPK and mTOR pathways in hypothalamus was also investigated. Treatment with leptin reduced food intake in exercised rats that were pretreated with vehicle, although no increase in sensitivity to leptin induced anorexia after pretreatment with anti-IL6 antibody, AICAR or Rapamycin was detected. The current study provides direct measurements of AMPK and mTOR signaling in the hypothalamus and documents altered sensitivity to these hormones in the hypothalamus of exercised rats in an IL-6-dependent manner. Increased responses of AMPK and mTOR to leptin may contribute to the appetite suppressive actions of exercise.
- Subjects
EXERCISE; PROTEIN kinases; HYPOTHALAMUS; LABORATORY rats; LEPTIN
- Publication
Diabetes, 2007, Vol 56, pA7
- ISSN
0012-1797
- Publication type
Article