Related Experiment Video
Updated: Jun 27, 2026
08:01
Measurement of Insulin- and Contraction-Stimulated Glucose Uptake in Isolated and Incubated Mature Skeletal Muscle from Mice
Published on: May 16, 2021
Central exercise action increases the AMPK and mTOR response to leptin
Eduardo R Ropelle1, Maria Fernanda A Fernandes, Marcelo B S Flores
1Department of Internal Medicine, FCM, State University of Campinas (UNICAMP), Campinas, São Paulo, Brazil.
Plos One
|December 5, 2008
Summary
Acute exercise enhances the effects of leptin on food intake by modulating the AMPK/mTOR pathway in the hypothalamus, potentially through IL-6 signaling. This suggests exercise may aid appetite control.
Area of Science:
- Metabolism and Endocrinology
- Neuroscience
- Exercise Physiology
Background:
- AMP-activated protein kinase (AMPK) and mammalian Target of Rapamycin (mTOR) are crucial for cellular energy homeostasis and leptin's regulation of food intake.
- Acute exercise enhances leptin sensitivity for food intake control, partly via Interleukin-6 (IL-6).
Purpose of the Study:
- To investigate if exercise modifies the hypothalamic AMPK and mTOR pathways in response to leptin, and if this is IL-6 dependent.
- To explore the role of AMPK and mTOR signaling in exercise-induced alterations of appetite regulation.
Main Methods:
- Rats underwent two 3-hour exercise sessions with a 45-minute rest.
- Hypothalamic AMPK/mTOR signaling pathways were analyzed post-leptin infusion in exercised versus control rats.
- Interventions included IL-6 infusion, AMPK activators (AICAR), and mTOR inhibitors (Rapamycin).
Main Results:
- Exercise potentiated leptin's suppression of food intake and its effects on hypothalamic AMPK/mTOR signaling in both lean and obese rats.
- IL-6 infusion reduced food intake, an effect blocked by AMPK activators or mTOR inhibitors.
- Exercise altered AMPK and mTOR pathway phosphorylation in response to leptin, suggesting a key role in appetite regulation.
Conclusions:
- Exercise potentiates leptin's appetite-suppressing effects in the hypothalamus via the AMPK/mTOR pathway.
- This potentiation may involve IL-6 signaling, contributing to exercise-mediated appetite control.
- Findings highlight the interplay between exercise, leptin, and central energy balance pathways.
Related Concept Videos
01:25cAMP-dependent Protein Kinase Pathways
Cyclic Adenosine Monophosphate (cAMP) is an essential second messenger that activates protein kinase A (PKA) and regulates various biological processes. A single epinephrine molecule binds to GPCR and activates several heterotrimeric G proteins, each stimulating multiple adenylyl cyclase, amplifying the signal, and synthesizing large numbers of cAMP molecules. Small changes in cAMP concentration affect PKA activity. The binding of four cAMP molecules induces a conformational change in PKA,...
01:22PI3K/mTOR/AKT Signaling Pathway
The mammalian target of rapamycin (mTOR) is a serine/threonine kinase that regulates growth, proliferation, and cell survival in response to hormones, growth factors, or nutrient availability. This kinase exists in two structurally and functionally distinct forms: mTOR complex 1 (mTORC1) and mTOR complex 2 (mTORC2). The first form (mTORC1) is composed of a rapamycin-sensitive Raptor and proline-rich Akt substrate, PRAS40. In contrast, mTORC2 consists of a rapamycin-insensitive companion...
03:03mTOR Signaling and Cancer Progression
The mammalian target of rapamycin or mTOR protein was discovered in 1994 due to its direct interaction with rapamycin. The protein gets its name from a yeast homolog called TOR. The mTOR protein complex in mammalian cells plays a major role in balancing anabolic processes such as the synthesis of proteins, lipids, and nucleotides and catabolic processes, such as autophagy in response to environmental cues, such as availability of nutrients and growth factors.
The mTOR pathway or the...
The mTOR pathway or the...
01:19Interactions Between Signaling Pathways
Signaling cascades usually lack linearity. Multiple pathways interact and regulate one another, allowing cells to integrate and respond to diverse environmental stimuli.
Convergence and divergence, and cross-talk between signaling pathways
Two distinct signaling pathways can converge on a single functional unit, which may either be a single protein or a complex of proteins. The response is either functionally distinct or synergistic between the two pathways but different from the response...
Convergence and divergence, and cross-talk between signaling pathways
Two distinct signaling pathways can converge on a single functional unit, which may either be a single protein or a complex of proteins. The response is either functionally distinct or synergistic between the two pathways but different from the response...
01:07MAPK Signaling Cascades
Mitogen-activated protein kinase, or MAPK pathway, activates three sequential kinases to regulate cellular responses such as proliferation, differentiation, survival, and apoptosis. The canonical MAPK pathway starts with a mitogen or growth factor binding to an RTK. The activated RTKs stimulate Ras, which recruits Raf or MAP3 Kinase (MAPKKK), the first kinase of the MAPK signaling cascade. Raf further phosphorylates and activates MEK or MAP2 Kinases (MAPKK), which in turn phosphorylates MAP...
01:30Regulation of Food Intake
Short-term regulation of food intake primarily involves neural signals from the gastrointestinal (GI) tract, blood nutrient levels, and GI tract hormones. Communication between the gut and brain via vagal nerve fibers plays a significant role in evaluating the contents of the gut. Clinical studies have shown that protein ingestion produces a more prolonged response in these nerve fibers compared to an equivalent amount of glucose. Additionally, the activation of stretch receptors caused by GI...