A study regarding the mechanism of hearing loss in development of endolymphatic hydrops in Meniere's disease

有人认为，膜迷路水转运调节功能的紊乱可能是内淋巴衰竭和淋巴周围衰竭时离子转运功能失衡的原因之一。这一失败导致了内淋巴积水，这是一种内耳的形态障碍。尽管其发生机制尚不清楚，但各种实验和临床证据表明，AVP可能参与了MD内淋巴积水的发展。在我们之前题为《MD内淋巴积水发生机制的研究》(Grant-in-aid for Science Research(C)(2))中，通过给予AVP在动物模型中发生听力损失。这种听力损失在某种程度上得到了修复。实验中AVP的剂量为0.02U/g，观察注射相同剂量的AVP后是否形成内淋巴积液。结果表明，相同剂量的AVP在光镜下未见内淋巴积水形成。这些结果表明，听力损失的发生没有内淋巴积液的形态障碍。因此，在我们的动物模型上，我们研究了耳蜗内淋巴D-C电位(EP)对AVP应用的影响。结果表明，AVP给药后2~10min，EP显著降低。认为在内淋巴积液形成和听力受损之前，血管纹的功能已经改变，下一步的研究计划通过给予AVP来观察血管纹的功能和形态变化。

It was thought that the disorder of accommodation in water transport in membranous labyrinth let the homeostatic function of ion transport in endo- and peri-lymph failure. This fail caused to endolymphatic hydrops that was a morphological disorder in inner ear. Though the mechanism of its occurrence still remains unclear, various lines of experimental and clinical evidence indicate a possible roll of AVP in development of endolymphatic hydrops in MD. In our previous study entitled "A study regarding the mechanism in development of endolymphatic hydrops in MD" (Grant-in-Aid for Scientific Research (C)(2), the hearing loss was occurred in the animal model by administering AVP. This hearing loss was sometime repaired. The purpose in present study was to elucidate the mechanism of this hearing loss.The dose of AVP in the experiments was 0.02units/g. It was investigated whether the endolymphatic hydrops was formed by administration of same dose of AVP. As the results, the endolymphatic hydrops was not formed in light microscope level by administration of same dose of AVP. These results mean that the hearing loss was occurred without the morphological disorder of endolymphatic hydrops. As the next step, it was necessary to investigate some physiological disorders in administration of AVP.Therefore, it was investigated whether the cochlear endolymphatic D-C Potential (EP) had an influence on the administrating AVP in our animal model. As the results, EP was decreased statistically in 2-10 minutes after administrating of AVP. It was thought that the function of stria vascularis was changed before the formation of endolymphatic hydrops and hearing was impaired.In next study, it was planed that the function and morphological change of stria vascularis were investigated by administrating AVP.