Exercise training prevents maturation-induced decreases in insulin receptor substrate-1 and phosphatidylinositol 3-kinase in rat skeletal muscle
| Autor: | Mariko Obayashi, Yoshiharu Oshida, Yoshiharu Shimomura, Atsushi Yoshimura, Taro Murakami, Yuzo Sato, Zhihao Li, Naoya Nakai, Ming Xu, Masaru Nagasaki, Noriaki Fujitsuka |
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| Rok vydání: | 2000 |
| Předmět: |
medicine.medical_specialty
Endocrinology Diabetes and Metabolism medicine.medical_treatment Physical exercise Phosphatidylinositol 3-Kinases Gastrocnemius muscle Endocrinology Physical Conditioning Animal Internal medicine medicine Animals Insulin RNA Messenger Rats Wistar Muscle Skeletal Pancreatic hormone biology Kinase Skeletal muscle Phosphoproteins Rats IRS1 Insulin receptor medicine.anatomical_structure Insulin Receptor Substrate Proteins biology.protein Female |
| Zdroj: | Metabolism. 49:954-958 |
| ISSN: | 0026-0495 |
| DOI: | 10.1053/meta.2000.6758 |
| Popis: | We have previously reported that exercise training prevents a maturation-induced decrease in insulin sensitivity and suggested that an improvement of insulin sensitivity by exercise training was attributable, in part, to an increase in insulin-sensitive GLUT-4 on the skeletal muscle plasma membrane. In this study, we examined the effects of maturation and exercise training on the gene expression and protein content of the components of post-insulin receptor signal transduction in rat skeletal muscle. Rats aged 3 weeks were sedentary or trained by voluntary running through 4 or 27 weeks of age, and then the rats in both the sedentary and trained groups were killed and the gastrocnemius muscle was immediately removed for analysis of mRNA and protein content. The concentration of mRNA and protein for insulin receptor substrate-1 (IRS-1) in sedentary rats significantly decreased with maturation (49% and 63%, respectively, at age 27 weeks v age 4 weeks), but in trained rats they did not decrease with maturation. Although the level of phosphatidylinositol 3-kinase (PI 3-kinase) mRNA in sedentary rats was not altered with maturation, PI 3-kinase protein in sedentary rats significantly decreased with maturation (73% at 27 weeks v 4 weeks). However, PI 3-kinase protein in trained rats did not decrease with maturation. These results suggest that the prevention of maturation-induced decreases in the protein content of IRS-1 and PI 3-kinase is involved in the mechanisms responsible for the improvement of insulin sensitivity by exercise training, and exercise training may affect transcriptional regulation of the IRS-1 gene and posttranscriptional regulation of PI 3-kinase expression. |
| Databáze: | OpenAIRE |
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