Gratton M A, Wright C G
Department of Otorhinolaryngology, University of Texas Southwestern Medical Center, Dallas 75235.
Pigment Cell Res. 1992 Feb;5(1):30-7. doi: 10.1111/j.1600-0749.1992.tb00779.x.
This report describes morphological alterations of the chinchilla stria vascularis seen 30 days after exposure to impulse noise. The observed changes included a dramatic increase in strial melanin content which occurred in 7 of 36 animals exposed to electronically synthesized impluses presented in various temporal patterns at either 135 or 150 dB peak SPL. In these animals, densely pigmented areas of stria 1.5 to 3 mm in length were found in the basal cochlear turn. Light and electron microscopic study revealed that these areas contained large numbers of melanin granules situated primarily in pale-staining cells of the middle layer of the stria. Unlike the pigment granules present in normal chinchilla stria, the melanosomes found in the noise-exposed material clearly showed ultrastructural features characteristic of eumelanin. Melanin granules were also observed in marginal and basal cells of the noise-exposed stria. In some cases, pigment granules which had apparently been expelled from the marginal cells were present in the endolymphatic space beneath Reissner's membrane and on the strial surface. These findings support the view that the melanin-bearing cells of the inner ear are capable of markedly increased activity in response to stressful conditions.
本报告描述了暴露于脉冲噪声30天后所观察到的灰鼠血管纹的形态学改变。观察到的变化包括，在36只暴露于以不同时间模式呈现的电子合成脉冲（峰值声压级为135或150分贝）的动物中，有7只动物的血管纹黑色素含量急剧增加。在这些动物中，在耳蜗基部转弯处发现了长度为1.5至3毫米的血管纹密集色素沉着区域。光镜和电镜研究显示，这些区域含有大量黑色素颗粒，主要位于血管纹中层的淡染细胞中。与正常灰鼠血管纹中存在的色素颗粒不同，在噪声暴露材料中发现的黑素体明显显示出真黑素的超微结构特征。在噪声暴露的血管纹的边缘细胞和基底细胞中也观察到了黑色素颗粒。在某些情况下，明显从边缘细胞排出的色素颗粒存在于Reissner膜下方的内淋巴间隙和血管纹表面。这些发现支持了这样一种观点，即内耳中含黑色素的细胞能够在应激条件下显著增加活性。
