Role of Vasopressin-Aquaporin2 System in the Formation of Endolymphatic Hydrops

2016 Fiscal Year Final Research Report

• Project/Area Number: 25293346
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Partial Multi-year Fund
• Section: 一般
• Research Field: Otorhinolaryngology
• Research Institution: Kobe University (2016); The University of Tokyo (2013-2015)
• Principal Investigator: Kakigi Akinobu 神戸大学, 医学(系)研究科(研究院), 特命教授 (60243820)
• Co-Investigator(Renkei-kenkyūsha): YAMASHITA SHINJI 東京大学, 先端科学技術センター, 教授 (40239968) ; SAKAMOTO TAKASHI 東京大学, 医学部附属病院, 講師 (50323548) ; EGAMI NAOYA 東京大学, 医学部附属病院, 講師 (10505895)
• Project Period (FY): 2013-04-01 – 2017-03-31
• Keywords: メニエール病 / 抗利尿ホルモン / アクアポリン / 内リンパ水腫 / OCT / イソソルビド

Outline of Final Research Achievements

Meniere’s disease（MD）is histologically characterized by endolymphatic hydrops in the inner ear. The mechanisms underlying overaccumulation of endolymph still remain an enigma. There is considerable evidence that water homeostasis in the inner ear is regulated partly via the vasopressin-aquaporin2 (VP-AQP2) system, suggesting that endolymphatic hydrops, a morphological characteristic of Meniere’s disease, may reflect the mal-regulation of the VP-AQP2 system in inner ear fluid.
In this study, we revealed the existence of AQP2 in the stria vascularis. Moreover, administration of vasopressin type2 receptor agonist induced formation of endolymphatic hydrops. We observed this phenomenon using OCT in vivo. Further, we observed the decompression effect of isosorbide on endolymphatic hydrops by OCT in vivo. These results seem to be useful to understand the underlining mechanisms of formation of endolymphatic hydrops.

Free Research Field

耳鼻咽喉科