IMPACT OF HEAVY METALS ON VESTIBULAR SENSORY ORGANS

该子项目是利用NIH/NCRR资助的中心赠款提供的资源的许多研究子项目之一。子项目和研究者（PI）可能从另一个NIH来源获得了主要资金，因此可以在其他CRISP条目中表示。所列机构为中心，不一定是研究者所在机构。人类的内耳包含听觉和平衡器官。长期接触重金属会损害内耳的听觉成分，导致听力损失。接触这种物质还会影响平衡器官，从而导致儿童和成人的失衡，而平衡器官是在微小的碳酸钙晶体（耳石）的帮助下发挥作用的。耳石的产生和功能受包埋的蛋白质物质控制。当有毒金属进入耳石的蛋白质基质时，可能会导致微小晶体形成异常，从而表现为听力和平衡障碍。为了了解重金属暴露对人类耳石生物矿化的影响，我们建议调查重金属，汞，镉和铅，在鱼的耳朵类似的生物矿物（耳石）的毒性影响。耳石器官也是由碳酸钙构成的。耳石中的蛋白质物质控制着耳石的晶体形式和大小。该假说基于重金属通过直接沉积以及与有机基质（蛋白质）结合而结合到生物矿物中的事实。根据暴露的程度，特定金属的毒性和含量，它们可能会抑制或改变耳石的正常发育和功能。为了验证这一假设，有人提出将斑马鱼暴露于水中的金属，然后将耳石取出并分析金属，以阐明它们在无机和有机物质之间的水平和分布。

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. The inner ear in humans contains hearing and balance organs. Chronic exposure to heavy metals causes damages to auditory component of the inner ear resulting in hearing loss. Exposure also causes imbalance in children and adults by affecting the balance organ that functions with the aid of tiny calcium carbonate crystals (otoconia). The production and function of the otoconia are controlled by the protein material embedded. Toxic metals when incorporate into the protein matrix of the otoconia may cause abnormalities in the formation of the tiny crystals that is consequently manifested by hearing and balance disorders. To understand the impact of heavy metal exposure on the biomineralization of human otoconia, we proposed to investigate toxic impact of heavy metals, mercury, cadmium and lead, on similar biominerals (otoliths) in the ears of fish. Otolith organs are also made of calcium carbonate. The protein material within an otolith controls the crystal form and size of the otolith. The hypothesis based on the fact that heavy metals incorporate to biominerals by direct deposition as well as by binding to the organic matrix (proteins). Depending on the magnitude of exposure, toxicity of particular metal and levels incorporated, they may inhibit or alter the normal development and function of the otolith. To test the hypothesis, it was proposed that zebrafish would be exposed to the metals in water, then the otoliths would be removed and analyzed for the metals to elucidate their levels and distribution between inorganic and organic material.