| Project/Area Number |
05671451
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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 |
Otorhinolaryngology
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| Research Institution | Kawasaki Medical School |
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Principal Investigator |
SATO Yukihiro Kawasaki Medical School, Otoloryngology, Assistant Professor, 医学部, 講師 (00215865)
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| Project Period (FY) |
1993 – 1994
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| Project Status |
Completed (Fiscal Year 1994)
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| Budget Amount *help |
¥1,200,000 (Direct Cost: ¥1,200,000)
Fiscal Year 1994: ¥400,000 (Direct Cost: ¥400,000)
Fiscal Year 1993: ¥800,000 (Direct Cost: ¥800,000)
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| Keywords | organ of corti / gap junction / capacitance / カルシウムイオン / CAMP |
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| Research Abstract |
Pairs or small groups of Hensen's cells were isolated from the top two turns of the guinea pig organ of the corti by agitation in a Ca^<2+> free buffer containing 1mg/ml trypsin. The cells were allowed to settle onto the glass coverslip at the bottom of a perfusion chamber and were continuously perfused with an ionic blocking solution. Cell capacitance was measured by integration of the capacitive transient in response to small voltage steps, with appropriate correction for series resistance. Ryanodine and caffeine were soluted with electrode solution and applied into the cells.
For fluorescence study the cochlea was incubated in 1mug/ml DiOC6 for 10min and rinsed three times. The supporting cells were isolated mechanically. Then fluorescent images were obtained using filters as for fluorescence.
After the whole cell configuration was established with one cell of a group, the pipette solution replaced that of the cell interior over the course of a few minutes. Input capacitance measures of ryanodine treated cells at a concentration of 10^<-6>-10^<-9> M indicated that 50% of the initially coupled cells uncoupled. Caffeine at a concnetration of 5*10^<-3>M also was effective. The fluorescence study showed existence of endoplastic reticulum in the supporting cells. Based on these data it was concluded that calcium was released from calcium storage, endoplasmic reticulum, and then the intracellular calcium concentration increased and uncoulpled the gap junction the organ of corti.
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