J Korean Diabetes Assoc.
2000 Dec;24(6):641-651.
Effects of High Fat Diet on Lipolysis in Skeletal Muscle and Adipose Tissue in Rats
- Affiliations
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- 1Department of Internal Medicine, Soonchunhyang University College of Medicine, Seoul, Korea.
- 2Department of Internal Medicine, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea.
- 3Department of Internal Medicine, Gachon Medical School, Incheon, Korea.
Abstract
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BACKGROUND: It has been hypothesized that increased fat oxidation reduces glucose
utilization in skeletal muscle, and is responsible for the insulin resistance associated
with obesity or high-fat feeding. In contrast, there have been reports that fat
oxidation capacity was decreased in skeletal muscles from insulin resistant subjects.
This study was undertaken to examine whether insulin resistance in high- fat fed rats
is associated with increased lipolysis in skeletal muscle and adipose tissue.
METHODS
Two groups of Sprague-Dawley rats were fed either high-fat or low-fat
diets for 4 weeks. Lipolysis in skeletal muscle and adipose tissue was determined
by measurement of interstitial glycerol concentrations by a microdialysis method in
basal and hyperinsulinemic-euglycemic clamp conditions.
RESULTS
In basal state, plasma glycerol levels and interstitial glycerol concen
trations of skeletal muscle, and adipose tissue were lower in high-fat fed than in
low-fat fed rats. The degree of suppression of glycerol release by the
hyperinsulinemia was smaller in the high-fat diet than in the low-fat diet group.
However, plasma and interstitial glycerol concentrations during the hyperinsul
inemic euglycemic clamps were also lower in the high-fat diet group.
CONCLUSION
Lipolysis was decreased in skeletal muscle and adipose tissue of insulin
resistant, high-fat fed rats. These results support the idea that limited fat oxidation
capacity resulting in lipid accumulation in tissues, rather than increased fat oxida
tion per se, is responsible for the insulin resistance associated with high-fat feeding.