1996 Fiscal Year Final Research Report Summary
Ion transport mechanism of marginal cells and basal cells dissociated form the stria vascularis in the inner ear
| Project/Area Number |
07671864
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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 |
Otorhinolaryngology
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| Research Institution | Kochi Medical School |
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Principal Investigator |
TAKEUCHI Shunji Kochi Medical School, Physiology, Research Associate, 医学部, 助手 (50188158)
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| Co-Investigator(Kenkyū-buntansha) |
IRIMAJIRI Akihiko Kochi Medical School, Physiology, Professor, 医学部, 教授 (30025605)
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| Project Period (FY) |
1995 – 1996
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| Keywords | Inner ear / Stria vascularis / Marginal cell / Basal cell / Ion transport |
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| Research Abstract |
(1) The basolateral membrane of isolated strial marginal cells was probed for conductive pathways by patch-clamp technique. Two types of channels, a nonselective cation channel (25 pS) and a Cl channel, (80 pS) were identified.
(2) Using the whole-cell patch-clamp technique, Cl-selective currents manifested by strial marginal cells were investigated. A large Cl conductance of 100 pS/cell was found from nonswollen cells in an isotonic solution.
(3) The whole-cell Cl conductance of the marginal cell varied in parallel with cell volume. The permeability sequence of this current was SCN>Br=Cl>F>NO_3>I>gluconate.
(4) Maxi-K channels were identified in the plasma membrane of basal cells. The physiological significance of these channels have not been determined.
(5) Effects of K channel blockers on the positive endocochlear potential (EP) of guinea pigs maintained by vascular perfusion were studied. The EP levels was reversibly blocked by Ba^<2+>, quinine and verapamil in the perfusate, but not by tetraethylammonium or 4-aminopyridine. These findings indicate an important role for a K conductance in the generation of EP.
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