| Project/Area Number |
03670130
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| Research Category |
Grant-in-Aid for General Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Research Field |
General medical chemistry
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| Research Institution | TEIKYO UNIVERSITY |
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Principal Investigator |
KASAHARA Michihiro Teikyo University, School of Medicine, Professor, 医学部, 教授 (40010102)
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| Co-Investigator(Kenkyū-buntansha) |
SHIOMORI Tsugunori Teikyo University, School of Economics, Lecturer, 経済学部, 講師 (90082320)
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| Project Period (FY) |
1991 – 1992
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| Project Status |
Completed (Fiscal Year 1992)
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| Budget Amount *help |
¥2,000,000 (Direct Cost: ¥2,000,000)
Fiscal Year 1992: ¥800,000 (Direct Cost: ¥800,000)
Fiscal Year 1991: ¥1,200,000 (Direct Cost: ¥1,200,000)
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| Keywords | Insulin / Glucose Transporter / Adipocyte / Placenta / Recycling / Translocation / Insulin-like growth factor-I / グルコ-ス輸送 / GLUT1 / SGLT1 / 腎臓 |
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| Research Abstract |
Significant advance has been achieved in the study of insulin action. Successful cloning of the insulin receptor had been reported. It has become clear that some patients with insulin-independent diabetes mellitus possess mutant insulin receptors. At the same time, an unexpected insulin-induced translocation of intracellular glucose transporter to plasma membrane has been implicated as a cause for insulin-induced activation of glucose transport.
We have proceed further on the study of glucose transporter translocation and extended the wide-ranged study of insulin reception and the cell biological study on the glucose transporter. The following is the major achivement we have made in this study.
1. We compared the time course of activation of glucose transport and the time course of GLUT1 & GLUT4 translocation in rat adipocytes. Transport activity and GLUT1 translocation showed a similar time course, on the other hand, GLUT4 translocation was slower. These results are suggestive of the importance of GLUT1 in the insulin action, which is apparently against a popular view of GLUT 4 preference.
2. Insulin-like growth factor-I(IGF-1) receptor was purified from human placenta. Rabbit antibody against the IGF-I receptor was raised. Tissues from patients with breast cancer showed elevated level of the IGF-I receptor, which is in accord with the observation that IGF-I binding activity is high in these tissues.
3. Immunofluoresent and immunoelectron microscopic studies revealed the GLUT1 transporter is abundant in the blood-tissue barriers such as the blood-brain barrier, the blood-ocular barrier and the placental barrier. Using similar techniques, SGLT1, a major Na-dependent glucose transporter is localized to the brush border membranes of small intestine and the proximal tubules of kidney, which is in concert with physiological observations.
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