2003 Fiscal Year Final Research Report Summary
Effect of chagnes in the pnoteip ex ession of MCTs on lactate metabolism during and after exercise
| Project/Area Number |
12680014
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
体育学
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| Research Institution | The University of Tokyo |
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Principal Investigator |
HATTA Hideo The University of Tokyo, Graduate School of Arts and Science, Associate Professor, 大学院・総合文化研究科, 助教授 (60208535)
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| Project Period (FY) |
2000 – 2003
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| Keywords | Lactate / Exercise / MCT1 / MCT4 |
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| Research Abstract |
We investigated whether the protein expression of lactate transporter (MGT=Monocarboxylate Transporter) changes after endurance training and other stimulus and also the relationship between changes in the MCTs and lactate metabolism during and after exercise. We made antibodies of MCT1 And MCT4 at first. We confirmed that muscle. specific abundance of these two MCTs in the skeletal muscle. There was a significant relationship between MCTI in the skeletal muscle and accumulated volume of nuining in mice with spontaneous running wheel, suggesting that total volume ofexercise can be a determinant of protein expression of MCTI. Endurance training, high intensity training also increased the protein level of MCTI. MCT4 was increased only after high intensity training in mice, suggesting intensity of exercise as the major determinant of increase in MCT4. In rats with streptozotocin induced diabetic condition, there were significant decreases in MCTI and MCT4 possibly because of decrease in carbohydrate metabolism in diabetic condition. Endurance training in the diabetic rats increased not only MCT1 but also MCT4. In order to investigate intracellular localization and function of MCTI, we checked specific sites for oxidation of lactate in the skeletal muscle. As lactate is oxidized mitochondria, we isolated mitochondria and measured mitochondria) MCTI. Significant increase was found in the mitochondria MCTI content after endurance training. There was a significant relationship between mitochondria) MCTI content and blood lactate concentration during endurance type running in rats. These results suggest that MCT 1 plays important roles for oxidation of lactate during exercise.
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