| Co-Investigator(Kenkyū-buntansha) |
IGUCHI Iroyoshi Osaka City University, Medicine Assistant, 医学部, 助手 (70271195)
KONISHI Kazuo Osaka City University, Medicine Assistant Professor, 医学部, 講師 (50145801)
OHASHI Yoshihiro Osaka City University, Medicine Associate Professor, 医学部, 助教授 (60160602)
YAMANE Hideo Osaka City University, Medicine Associate Professor, 医学部, 助教授 (60145787)
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| Research Abstract |
We examined the utility of dye extrusion method for assesing the cochlear hair cell death in the guinea pig. This methods is not only accurate but also simple, easy and useful for screening of hair cell death in the cochela after several conditions. NOC 5, a NO donor, and the cleavage products arising from it after production of NO have ototoxic effects on the cochlea. Though NOC-5 is useful for study of NO, its cleavage products are also ototoxic. 0K432, a heat- and penicillin-treated lyophilized powder of a low virulent Su strain of streptococcus pyo genes, was injected into the perilymphatic space of guinea pigs in order to determine the kinetics of exudation of inflammatory cells into the cochlea over a 7-day period and which findings suggest that the inner ear can undergo induction of macrophage exdation by OK432 treatment as has previously been observed for other organs. we examined whether extrusion of hair cells itself can trigger mitotic cell proliferation. We compared cell proliferative activity after collagenese treatment with that after a intense sound exposure in vitro. In concluision, cell death and degeneration preceding defection of hair cells may play key roles in hair cell regeneration, as may EGF and soluble factors in FBS as well. The cause of aminoglycoside ototoxicity has been still unknown. In this study, we investigated whether superoxide anion radical (O_2^-) was emerged or not in the cochlea of guinea pig treated with kanamycin(KM). KM in gelfoam placed on the round window membrane was transported from the lower to upper cochlear turn over time. Of emerged on the hair of outer hair cells coincident with KM transportation to the organ of Corti. On the hair of inner hair cells the emergence of O_2^- was not observed. These observations suggest the posibility that the emergence of O_2^- plays a role in the early stage of KM ototoxicity.
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