Overnutrition caused by overeating is associated with insulin and leptin resistance through IKKbeta activation and endoplasmic reticulum (ER) stress in the hypothalamus. Here we show that physical exercise suppresses hyperphagia and associated hypothalamic IKKbeta/NF-kappaB activation by a mechanism dependent upon the pro-inflammatory cytokine interleukin (IL)-6. The disruption of hypothalamic-specific IL-6 action blocked the beneficial effects of exercise on the re-balance of food intake and insulin and leptin resistance.
View Article and Find Full Text PDFAMP-activated protein kinase (AMPK) and mammalian Target of Rapamycin (mTOR) are key regulators of cellular energy balance and of the effects of leptin on food intake. Acute exercise is associated with increased sensitivity to the effects of leptin on food intake in an IL-6-dependent manner. To determine whether exercise ameliorates the AMPK and mTOR response to leptin in the hypothalamus in an IL-6-dependent manner, rats performed two 3-h exercise bouts, separated by one 45-min rest period.
View Article and Find Full Text PDFProper activation of phosphoinositide 3-kinase-Akt pathway is critical for the prevention of tumorigenesis. Recent data have characterized a negative feedback loop, wherein mammalian target of rapamycin (mTOR) blocks additional activation of the Akt/mTOR pathway through inhibition insulin receptor substrate 1 (IRS-1) function. However, the potential of IRS-1 inhibition during rapamycin treatment has not been examined.
View Article and Find Full Text PDFLifestyle interventions including exercise programmes are cornerstones in the prevention of obesity-related diabetes. In this study, we demonstrate that a single bout of exercise inhibits high-fat diet-induced insulin resistance. Diet-induced obesity (DIO) increased the expression and activity of the protein tyrosine phosphatase 1B (PTP1B) and attenuated insulin signalling in gastrocnemius muscle of rats, a phenomenon which was reversed by a single session of exercise.
View Article and Find Full Text PDFProlonged exercise of medium to high intensity is known to promote a substantial effect on the energy balance of rats. In male rats, moderately to severely intense programs lead to a reduction in food intake. However, the exact causes for the appetite-suppressive effects of exercise are not known.
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