Exercise training and clenbuterol reduce insulin resistance of obese Zucker rats
| Autor: | John L. Ivy, Miriam Y. Cortez, C. E. Torgan, J. T. Brozinick, E. A. Banks, R. E. Wilcox |
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| Rok vydání: | 1993 |
| Předmět: |
Agonist
medicine.medical_specialty Physiology medicine.drug_class Endocrinology Diabetes and Metabolism medicine.medical_treatment Physical exercise Citrate (si)-Synthase Electron Transport Complex IV Insulin resistance Physical Conditioning Animal Physiology (medical) Internal medicine medicine Animals Insulin Aerobic exercise Clenbuterol Obesity Pancreatic hormone Dose-Response Relationship Drug business.industry Muscles Body Weight Methylglucosides Skeletal muscle Biological Transport Glucose Tolerance Test medicine.disease Rats Rats Zucker Receptors Adrenergic Glucose Endocrinology medicine.anatomical_structure 3-O-Methylglucose Female Insulin Resistance business medicine.drug |
| Zdroj: | American Journal of Physiology-Endocrinology and Metabolism. 264:E373-E379 |
| ISSN: | 1522-1555 0193-1849 |
| DOI: | 10.1152/ajpendo.1993.264.3.e373 |
| Popis: | This study compared the effects of aerobic exercise training and chronic administration of the selective beta 2-adrenergic agonist clenbuterol on whole body and skeletal muscle insulin resistance in obese (fa/fa) Zucker rats. Obese rats were randomly assigned to training, clenbuterol, or sedentary control groups. Lean littermates served as a second control group. After 4-5 wk of treatment, an oral glucose tolerance test was performed, followed 1 wk later by hindlimb perfusion, during which time the rates of glucose uptake and 3-O-methyl-D-glucose (3-MG) transport were assessed in the presence of a submaximal (500 microU/ml) insulin concentration. Training resulted in a significant increase in citrate synthase and cytochrome oxidase activity in the recruited muscles. Clenbuterol induced a large increase in muscle mass but provoked a significant decrease in oxidative enzyme activity and beta-adrenergic receptor density. Both treatments increased glucose tolerance and reduced the postglucose insulin response, with the improvements being more pronounced in the clenbuterol group. However, only exercise training improved insulin-stimulated hindlimb muscle glucose uptake (11.37 +/- 0.65, 8.73 +/- 0.77, and 8.27 +/- 0.41 mumol.g-1.h-1 for trained, clenbuterol, and sedentary control groups, respectively) and 3-MG transport. These results suggest that aerobic exercise training attenuated the insulin-resistant condition in the obese Zucker rat by a mechanism other than or in addition to beta 2-adrenergic receptor activation. |
| Databáze: | OpenAIRE |
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