内耳蝸牛血管条における細胞外空間のK+濃度・電位と蝸牛内高電位の関連の解析

DOI
  • 任 書晃
    大阪大学大学院医学系研究科分子細胞薬理学教室 京都府立医科大学耳鼻咽喉科学教室
  • 日比野 浩
    大阪大学大学院医学系研究科分子細胞薬理学教室
  • 土井 勝美
    大阪大学医学部耳鼻咽喉科学教室
  • 鈴木 敏弘
    京都府立医科大学耳鼻咽喉科学教室
  • 久 育男
    京都府立医科大学耳鼻咽喉科学教室
  • 倉智 嘉久
    大阪大学大学院医学系研究科分子細胞薬理学教室

書誌事項

タイトル別名
  • Endocohlear potential is controlled by the extracellular K+-dynamics via K+-transport apparatuses in cochlear stria vascularis of inner ear.

抄録

A cochlear extracellular fluid, endolymph, has 150 mM K+ and positive potential of ∼+80 mV called "endocochlear potential (EP)". EP is essential for hearing. K+-transport via an epithelial tissue "stria vasclularis" in the lateral wall is crucial for maintaining the high K+ and EP. Stria vascularis comprises marginal (MCs) and intermediate (ICs) cells. The extracellular space sandwiched by the two is referred as "intrastrial space (IS)" and harbors low K+ of ∼2 mM and high potential of ∼+90 mV. This unique property is proposed to be an origin of EP and achieved by cooperation of Na+,K+,2Cl-cotransporter (NKCC) and Na+,K+-ATPase at the basolateral membrane of MCs and K+ channel at the apical site of ICs. However, the mechanism for its establishment is unknown. We thus measured the potential and K+ concentration ([K+]) of IS with a double-barreled electrode while applying furosemide, a NKCC-blocker, and anoxia, which dysfunctions Na+,K+-ATPase. Strial perfusion of furosemide largely declined the potential and increased [K+] in IS as well as reduced EP. Anoxia caused the same effect. The amplitude of change in IS-potential and EP paralleled that in K+ equilibrium potential toward IS. Hence, low [K+] in IS maintained by NKCC and Na+,K+-ATPase in MCs may promote [K+] diffusion via K+ channel in ICs, which forms IS potential and EP. [J Physiol Sci. 2007;57 Suppl:S108]

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詳細情報 詳細情報について

  • CRID
    1390001205727568768
  • NII論文ID
    130007038757
  • DOI
    10.14849/psjproc.2007.0.108.1
  • データソース種別
    • JaLC
    • CiNii Articles
  • 抄録ライセンスフラグ
    使用不可

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