Glucose oversupply increases Delta9-desaturase expression and its metabolites in rat skeletal muscle
Autor: | Michael Haap, Fausto Machicao, HU Häring, Erwin Schleicher, Walter Renn, H. P. T. Ammon, Hans Günther Wahl, M. Kresi, B. Houdali, V. Nguyen |
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Rok vydání: | 2002 |
Předmět: |
medicine.medical_specialty
Endocrinology Diabetes and Metabolism medicine.medical_treatment Biology Fatty Acids Nonesterified Diglycerides chemistry.chemical_compound Insulin resistance Internal medicine Internal Medicine medicine Animals RNA Messenger Rats Wistar Muscle Skeletal Pancreatic hormone Phospholipids Triglycerides chemistry.chemical_classification Triglyceride Dose-Response Relationship Drug Insulin Fatty Acids Skeletal muscle medicine.disease Rats Stearoyl-CoA Desaturase Dose–response relationship medicine.anatomical_structure Enzyme Endocrinology Glucose chemistry Female |
Zdroj: | Diabetologia. 46(2) |
ISSN: | 0012-186X |
Popis: | Previous studies have shown that prolonged glucose infusion causes insulin resistance and triglyceride accumulation in rat skeletal muscle. In this study, we investigated a possible relationship between insulin resistance and the composition of different accumulated lipid fractions in rat skeletal muscle.Continuous glucose infusion was carried out in rats for 7 days. Lipids were extracted from skeletal muscle, separated by thin layer chromatography and fatty acid composition of phospholipids, triglycerides, diglycerides, free fatty acids and cholesterol esters fractions was analysed by gas chromatography. Delta9-Desaturase mRNA was measured by real time polymerase chain reaction. The enzyme activity was measured in the microsomal fractions.Prolonged glucose infusion (5 days) increased the relative content of palmitoleic acid (16:1 N7) several-fold (2.3- to 5.8-fold) in four out of five lipid fractions and enhanced oleic acid (18:1 N9) two-fold in three lipid fractions suggesting increased Delta9-desaturase activity while the content of several polyunsaturated fatty acids was reduced. In parallel, Delta9-Desaturase mRNA contents and enzyme activities in skeletal muscle were increased 10-fold, 75-fold, 2.6-fold and 7.7-fold after 2 and 5 days of glucose infusion, respectively.Our results suggest that long-term glucose oversupply induces a rapid increase in Delta9-desaturase expression and enzyme activity in skeletal muscle which leads to fast and specific changes in fatty acid metabolism possibly contributing to the insulin resistance in this animal model. |
Databáze: | OpenAIRE |
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