Acute Manganism Induces Ototoxicity of Mice
| Autor: | Yu-Pu Han, 韓鈺埔 |
|---|---|
| Rok vydání: | 2014 |
| Druh dokumentu: | 學位論文 ; thesis |
| Popis: | 102 In vitro, overdose of manganese is toxic to auditory nerve fibers as well as spiral ganglion neurons and cochlear hair cells. In 2011, Ding and his colleagues published a study in Neurotoxicology showing for the first time that low levels of manganese initially damage neurons and sensory hair cells in the inner ears of rats. To understand the mechanism for manganese-induced auditory impairment, we assessed the degree of hearing impairment and the cochlear histopathological damage in ICR mouse model resulting from various levels of manganese. The auditory brainstem response (ABR) recording was used to determine and compare the auditory threshold in ICR mice after 5 times subcutaneous injection of saline, low (10 mg/kg/day) or high dose (50 mg/kg/day) of manganese chloride. Immunochemistry staining techniques were used to compare expression of prestin, a cochlear motor protein, and cleaved caspase-3, a apoptosis protein, in the cochlea of ICR mice. Our results show that the ABR thresholds of ICR mice were significantly elevated with low and high dose of manganese treatments. Although the difference of prestin expression in outer hair cells was not observed among ICR mice with subcutaneous injection of saline, low and high dose of manganese. The apoptosis-related cleaved caspase-3 was obviously observed in outer hair cells, spiral ganglion neurons, and stria vascularis cells in the cochlea of ICR mice with subcutaneous injection low and high dose of manganese. Thus we suggest that the cochlear apoptosis may be involved in manganese-induced auditory impairment. |
| Databáze: | Networked Digital Library of Theses & Dissertations |
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