1999 Fiscal Year Final Research Report Summary
Ion transport the cells constituting the cochlear stria vascularis
| Project/Area Number |
09671749
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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, Associate professor, 医学部, 助教授 (50188158)
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| Project Period (FY) |
1997 – 1999
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| Keywords | inner ear / stria vascularis / ion transport / gap junction / potassium channel / chloride channel |
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| Research Abstract |
1. Intermediate cells (melanocytes), capillary endothelial cells and pericytes were connected by gap junctions. The above finding adds endothelial cells and pericyies to the current "two-cell" model of the stria vascularis.
2. Elongated pericyte-like cells connecting discrete capillaries were found in the stria vascularis. These cells may provide mechanical strength to the tortuous capillary network in the stria vascularis
3. The development of capillary network in the stria vascularis and in the underlying spiral ligament was investigated by conventional electron microscopy and confocal laser microscopy in association with vascular labeling with fluorescent gelatin.
4. The activity of Na-K-C1 cotransporter in the epithelial marginal cell was proved at the single cell level.
5. The membrane potential of dissociated marginal cells was largely dependent on C1 conductance in the basolateral membrane.
6. The activity of glucose transporter (GLUT) in the marginal cell was proved using the autofluorescence derived from NADH in mitochondria.
7. Two types of KィイD1+ィエD1 channels in the intermediate cell were found by the whole-cell patch clamp technique, an inward rectifier KィイD1+ィエD1 channel and a voltage-dependent KィイD1+ィエD1 channel. The membrane potential of the intermediate cell was determined by both channels. It was speculated that the membrane potential of the intermediate cell Was reflected to the positive endocochlear potential.
8. Immunological activity for an inward rectifier KィイD1+ィエD1 channel (Kir4. 1) was found in the stria vascularis, and this immunoreactivity localized to the intermediate cell.
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