1994 Fiscal Year Final Research Report Summary
Hoemeostais of inne ear on the point of non-specic defense
| Project/Area Number |
04671047
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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 | OSAKA CITY UNIVERSITY |
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Principal Investigator |
YAMANE Hideo Osaka City University Medical School Assoc.professor, 医学部, 助教授 (60145787)
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| Co-Investigator(Kenkyū-buntansha) |
TAKAHASHI Kenichi Osaka Prefectural College of Health Science Professor, 医療技術短期大学部, 教授 (40089959)
KONISHI Kazuo Osaka City University Medical School Assis.professor, 医学部, 講師 (50145801)
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| Project Period (FY) |
1992 – 1994
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| Keywords | Inner ear / Cochlea / Stria vascularis / Non-specific defense / Free radical / NK cell / Acoustic trauma / K-562 |
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| Research Abstract |
In this experiment ethiologically unnown iner ear disease has been studied to clarify the non-specific defense mechanism (first defense mechanism) of the inner ear against pathogen. K-562 myelogenous leukemia cells were injected into the guinea pig perilymphatic space through the round window membrane and the raction of the inner ear was observed on day 1 to day 9. NK cells which were positive for anti-asialo GM1 appared in the perilymphatic space on day 7 when most of K-562 cells were still intact. On day 9 there were many K-562 cells with adherent phlogocytes in the perilymph and were mostly degenerated. The emergence of NK cells was much later in the perilympahtic space than in the skin which was also injected with K-562 cells. And there is a possibility that this delay can lead to the irreversiable change of cochlea due to pathogens before the mobilization of NK cells. In addition, the humoral factors in the inner ear fluid was not so powerful in suppresing viral infection and the endolympohatic sac didnot seem to play an important role in the defense against this pathiogen to rescue the cochlea. In consequence, the inner ear seems to be an environment which is relatively difficult for immunocompetent cells to perform their functions.
The effect of acoustic trauma on cochlear strial circulation was investigated imuunohistologically in the guinea pig. Kanamycin was used as a tracer of blood flow. Besides, histochemical examination were made to ascertain the emergence of free radicals in the cochlea after acoustic trauma. The blood flow in the stria vascularis was greatly diminished. The cause of acoustic trauma is obscure. But superoxide anion radicals (O_2) may be related to strial blood cieculation and affect strial function.
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