| Project/Area Number |
61480360
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| Research Category |
Grant-in-Aid for General Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Research Field |
Otorhinolaryngology
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| Research Institution | Miyazaki Medical College |
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Principal Investigator |
TAMOTSU Morimitsu Professor, Faculty of Medicine, Miyazaki Medical College, 医学部, 教授 (40038675)
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| Co-Investigator(Kenkyū-buntansha) |
MAKINO Kouji Assistent, Faculty of Medicine, Miyazaki Medical College, 医学部, 助手 (00145434)
IDE Minoru Assistent, Faculty of Medicine, Miyazaki medical College, 医学部, 助手 (00128365)
NAKANO Takayuki Lecturer, Kagoshima Immacurate Heart College, 講師 (30155783)
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| Project Period (FY) |
1986 – 1987
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| Project Status |
Completed (Fiscal Year 1987)
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| Budget Amount *help |
¥6,300,000 (Direct Cost: ¥6,300,000)
Fiscal Year 1987: ¥500,000 (Direct Cost: ¥500,000)
Fiscal Year 1986: ¥5,800,000 (Direct Cost: ¥5,800,000)
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| Keywords | vanadium / Na / K-ATPase / endocochlear DC potential / 発光法 |
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| Research Abstract |
Depressive effect of vanadate on endocochlear DC potential (EP) has been recognized electrophysiologically in the guinea pig cochlea.
To clarify the effect of vanadate on Na,K-ATPase in the stria vascularis, the activity of Na,K-ATPase in the lateral cochlear wall including the stria vascularis of the gunea pig was measured with a high performance liquid chromatography and a lumiphotometer. the total ATPase was 4.25 x 10 mole ATP/mg dry weight/min. and the ouabain sensitive ATPase, that is Na,K- ATPase, was 2.73 of same unit.
The activity of Na,K-ATPase in the cochlea could be inhibited by 0.5 uM of Ouabain or 0.2 uM of Vanadate completely.
Then, the antagonistic effect of Ascorbic acid for vanadate in the guinea pig cochlea was studied electrophysiologicaly. As the results, the activity of vanadate was inhibited to the level of 48 % with 10 ul of 10 mM Ascorbic acid and almost completely with 10 ul of 20 mM Ascorbic acid.
The chemical process of inhibition of vanadate on Na.K-ATPase was discussed. From the results obtained, it could be concluded that vanadate might be an important substance in the maintenance of EP in the cochlea.
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