1997 Fiscal Year Final Research Report Summary
Induction of autoimmune sensori neural heaving loss
| Project/Area Number |
08671994
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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 | Kansai Medical University |
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Principal Investigator |
IWAI Hiroshi KANSAI MEDICAL UNIVERSITY,DEPARTMENT : FUCULTY OF MEDICINE ASSITANT PROFESSOR, 医学部, 講師 (10232638)
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| Co-Investigator(Kenkyū-buntansha) |
TOMODA Koichi KANAZAWA MEDICAL UNIVERSITY,DEPARTMENT : FUCULTY OF MEDICINE PROFESSOR, 医学部, 教授 (50164041)
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| Project Period (FY) |
1996 – 1997
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| Keywords | autoimmune / sensorineural hearing loss / lymphocyte / bone marrow / histamine receptor / vestibular hair cells / crista ampullaris / charge barrier |
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| Research Abstract |
1.The MRL/1pr mouse manifests autoimmune sensorineural hearing loss (SHL) with cochlea pathology at 20 weeks of age. We examine the effects of injecting MRL/1pr lymphocytes (splenocytes) or bone marrow cells on the development of SHL in severe combined immunodeficient (SCID) mice, which originally develop neither SHL nor cochlea pathology. SCID mice were injected with these cells from MRL/1pr mice. Flow cytometric analyzes indicated the proliferation of the lymphocytes from injected donor cells in the mice 20 weeks after injection. Autoimmune SHL and cochlea pathology were observed in the host SCID mice injected donor cells. These findings suggest that the development of SHL and cochlea pathology attribute to the defects of bone marrow cells of donor mice and lymphocytes or derived from the bone marrow cells, but not of host cochlea.
2.The effect of histamine in the guinea pig isolated vestibular hair cells were examined by measuring the dynamic change of intracellular free calcium ion
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([Ca^<2+>] i) concentration using calcium sensitive dye Fura-2. We demonstrated that the histamine-induced response in the vestibular hair cells are mediated by H1, H2 and H3 receptors and resulted in a rise of [Ca^<2+>]i due to an influx of Ca^<2+> from the extracellular space and a release from intracellular stores. These data suggest that under immune-pathological conditions of the inner ear, histamine released from the mast cells distributed in the endolymphatic sac may act through receptors located on the vestibular hair cells membrane and may regulate the cell function and the signal transduction in the vestibular nerve-hair cell afferent system.
3.We obtained anionic sites in the epithelial and capillary basement membranes in the dark cell area of the crista ampullaris in the guinea pig. The immersion method with cationic tracer polyethyleneimine (PEI) was applied. Electromicroscopically, the arrangement of PEI particles was observed as two strata along the basement membrane. When using furosemide, stria vascularis and the dark cells had changed with pathological findings of interstitial edema and PEI particles reduced in number. It is suggested that the PEI particles reflect different conditions of charge barrier in the basement membrane, with influences the production or absorption on the inner ear fluid. Less
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Research Products
(6 results)
