Related Experiment Videos
Leptin directly alters lipid partitioning in skeletal muscle
D M Muoio1, G L Dohm, F T Fiedorek
1Department of Nutrition, University of North Carolina at Chapel Hill, 27599, USA.
Diabetes
|August 1, 1997
Summary
Leptin directly impacts skeletal muscle metabolism. This study shows leptin enhances fatty acid oxidation and reduces fat storage, while counteracting insulin
Area of Science:
- Endocrinology
- Metabolic Physiology
- Skeletal Muscle Biology
Background:
- Leptin is a key hormone regulating adiposity and energy balance.
- Skeletal muscle is a critical site for energy metabolism and expresses leptin receptors.
Purpose of the Study:
- To investigate the direct effects of leptin on glucose and fatty acid metabolism in mouse skeletal muscles.
- To determine how leptin interacts with insulin in regulating muscle fuel utilization and storage.
Main Methods:
- Isolated mouse soleus and extensor digitorum longus (EDL) muscles were treated with insulin, leptin, or both.
- Radioactive tracers ([14C]glucose and [14C]oleate) were used to measure substrate oxidation and incorporation into glycogen and triacylglycerol (TAG).
Main Results:
- Leptin significantly increased fatty acid oxidation and decreased fatty acid incorporation into TAG in soleus muscle.
- Leptin attenuated both the fatty acid oxidation and lipogenic effects of insulin when co-administered.
- Hormonal effects were less pronounced in EDL muscle, and leptin did not affect insulin-stimulated glucose metabolism.
Conclusions:
- Leptin exerts direct, acute effects on skeletal muscle fuel metabolism, primarily enhancing fatty acid utilization.
- Leptin modulates the actions of insulin in skeletal muscle, influencing fatty acid oxidation and storage.