OTOTOXICITY OF CHEMICAL ASPHYXIANTS AND NOISE

听觉刺激的受体细胞特别容易受到 由于血液的有限特性而导致氧分压降低 供给内耳。 电生理数据表明， 窒息会干扰听力，但轻度的，长期的 缺氧对听觉系统的影响尚未研究。 的一个目的 这项调查是为了确定亚慢性暴露于化学品 窒息剂的剂量与在职业卫生中广泛遇到的水平有关， 和环境设置产生耳毒性。 慢性和脉冲噪声 可能会导致听觉损伤，但这是否是通过机械 创伤或代谢衰竭是不确定的。 因为有数据显示 这表明，噪音降低了内淋巴液中的氧张力， 中阶并对内耳产生血管损伤， 假设噪声引起的听觉丧失可能是由于抑郁症， 氧气可用性 如果噪音确实通过限制氧气来干扰听力 或者如果它损害了内耳血管结构， 合理的假设是，噪音会加强耳毒性作用， 化学窒息物暴露 本提案的最终目的是 说明噪音与化学窒息剂之间相互作用的性质 exposure. 所使用的方法包括测量 通过低强度测试刺激和随后的听觉惊吓反射 内耳的组织学检查。

The receptor cells for acoustic stimuli are particularly vulnerable to reduced oxygen tension because of the limited characteristics of blood supply to the inner ear. Electrophysiological data have demonstrated that asphyxiation disrupts audition, but the consequences of mild, prolonged hypoxia upon the auditory system have not been investigated. One aim of this investigation is to determine whether subchronic exposure to chemical asphyxiants at doses relevant to levels widely encountered in occupational and environmental settings produces ototoxicity. Chronic and impulse noise can induce auditory damage, but whether this occurs through mechanical trauma or by metabolic exhaustion is uncertain. Because there are data which show that noise reduces oxygen tension in the endolymph fluid of the scala media and produces vascular damage to the inner ear, it has been hypothesized that noise induced auditory loss may result from depressed oxygen availability. If noise does disrupt hearing by restricting oxygen to the Corti Organ or if it damages inner ear vascular structures it is logical to assume that noise would potentiate the ototoxic effects of chemical asphyxiant exposure. The final aim of this proposal will be to specify the nature of the interaction between noise and chemical asphyxiant exposure. The methods to be used include measures of modulation of the acoustic startle reflex by low intensity test stimuli and subsequent histological examination of the inner ear.