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Hyperglycemia- and hyperinsulinemia-induced alteration of adiponectin receptor expression and adiponectin effects in L6 myoblasts
- Source :
- Journal of Molecular Endocrinology. 35:465-476
- Publication Year :
- 2005
- Publisher :
- Bioscientifica, 2005.
-
Abstract
- Adiponectin has been shown to regulate glucose and fatty acid uptake and metabolism in skeletal muscle. Here we investigated the role of the recently cloned adiponectin receptor (AdipoR) isoforms in mediating effects of both globular (gAd) and full-length (fAd) adiponectin, and their regulation by hyperglycemia (25 mM, 20 h) and hyperinsulinemia (100 nM, 20 h). We used L6 rat skeletal muscle cells, which were found to express both AdipoR1 and AdipoR2 mRNA in a ratio of over 6:1 respectively. Hyperglycemia and hyperinsulinemia both decreased AdipoR1 receptor expression by approximately 50%, while the latter induced an increase of approximately threefold in AdipoR2 expression. The ability of gAd to increase GLUT4 myc translocation, glucose uptake, fatty acid uptake and oxidation, as well as AMP-activated protein kinase (AMPK) and acetyl-CoA carboxylase (ACC) phosphorylation, was decreased by both hyperglycemia and hyperinsulinemia. Interestingly, hyperinsulinemia induced the ability of fAd to elicit fatty acid uptake and enhanced fatty acid oxidation in response to fAd. In summary, our results suggest that both hyperglycemia and hyperinsulinemia cause gAd resistance in rat skeletal muscle cells. However, hyperinsulinemia induces a switch toward increased fAd sensitivity in these cells.
- Subjects :
- medicine.medical_specialty
DNA, Complementary
Myoblasts, Skeletal
Glucose uptake
Receptor expression
Biological Transport, Active
Gene Expression
Receptors, Cell Surface
AMP-Activated Protein Kinases
Protein Serine-Threonine Kinases
Biology
Cell Line
Mice
Endocrinology
Multienzyme Complexes
Hyperinsulinism
Internal medicine
Hyperinsulinemia
medicine
Animals
Molecular Biology
Beta oxidation
Adiponectin receptor 1
chemistry.chemical_classification
Glucose Transporter Type 4
Base Sequence
Adiponectin
Fatty Acids
nutritional and metabolic diseases
Fatty acid
medicine.disease
Recombinant Proteins
Rats
Glucose
chemistry
Hyperglycemia
biology.protein
Receptors, Adiponectin
Oxidation-Reduction
hormones, hormone substitutes, and hormone antagonists
GLUT4
Acetyl-CoA Carboxylase
Subjects
Details
- ISSN :
- 14796813 and 09525041
- Volume :
- 35
- Database :
- OpenAIRE
- Journal :
- Journal of Molecular Endocrinology
- Accession number :
- edsair.doi.dedup.....69cd2bd7036974c3bebea810860244db