重金属耳毒性

Ototoxic effects of heavy metals

许多重金属都是机体所需的重要微量元素,但是过量摄取重金属及其化合物则可造成机体多种器官的严重损害。重金属及其化合物可通过各种途径进入机体并在体内积累致病,但不同种类的重金属损害机体组织的主要靶器官却并不完全相同,所以不同的重金属中毒往往产生各种不同的临床症状。重金属及其化合物可通过血液循环或脑脊液或圆窗膜等不同途径进入内耳,在内耳积累的各种重金属都可损害内耳感觉器官,这些遭到重金属破坏的内耳器官包括耳蜗和前庭的感觉上皮和与之相联系的耳蜗和前庭的神经节及神经纤维,从而造成听觉障碍和平衡障碍。本文综述了铅、汞、镉、砷、锰、钴、锡、铂等重金属对内耳的毒性作用及相关毒性机制,以期提高人们对重金属耳毒性的警觉和认识。

Many heavy metals are essential trace elements. However, heavy metal pollution can cause toxic effects to organism and ecosystem. Heavy metals and their compounds can enter the body through contamination of food, water, air, or absorption directly through the skin. Since the heavy metals are not completely metabolized by the organism, they are gradually accumulated in the tissue until reach the critical level causing toxic effects. Heavy metals and their compounds can injure almost all organs in varying degrees.However, different heavy metal may not target identical organ, whereby different heavy metal poisoning often exhibit a variety of clinic symptoms. To exert the toxic effects of heavy metals to the inner ear, the heavy metals and their compounds must first be transported into the inner ear from the bloodstream, cerebrospinal fluid, or round window membrane through different approaches, and then result in the damage to sensory hair cells and / or nerve system in the inner ear. Eventually lead to hearing impairment and balance disorders. The lead, mercury, cadmium, arsenic, manganese, cobalt, tin, platinum, copper are commonly encountered heavy metals in the environmental pollution. All these heavy metals can damage the auditory system directly or indirectly. In order to raise awareness of heavy metal ototoxicity, we have reviewed the ototoxic effects of various heavy metals and their possible toxic mechanisms in current article.