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Analysis of calcium ion transition in the cochlear fluids under cochlear blood flow disturbance

Research Project

Project/Area Number 08671949
Research Category

Grant-in-Aid for Scientific Research (C)

Allocation TypeSingle-year Grants
Section一般
Research Field Otorhinolaryngology
Research InstitutionUniversity of Tsukuba

Principal Investigator

ITO Zenya  Institute of Clinical Medicine, University of Tsukuba Assistant Professor, 臨床医学系, 講師 (20241812)

Project Period (FY) 1996 – 1998
Project Status Completed (Fiscal Year 1998)
Budget Amount *help
¥2,100,000 (Direct Cost: ¥2,100,000)
Fiscal Year 1998: ¥400,000 (Direct Cost: ¥400,000)
Fiscal Year 1997: ¥200,000 (Direct Cost: ¥200,000)
Fiscal Year 1996: ¥1,500,000 (Direct Cost: ¥1,500,000)
Keywordscalcium / cochlea / perilymph / endolymph / ischemia / permeability / diffusion / pH / 内耳 / 局所虚血 / 炭酸ガス / カルシウムイオン
Research Abstract

Homeostasis of calcium ion (Ca^<2+>) activities in the cochlear fluids are considered to be essential to maintain the function of the cochlea. Since local ischemia in the inner ear could disrupt the homeostasis, Ca^<2+> activities in perilymph and endolymph were monitored during and after local ischemia induced by pressing a labyrinthine artery in the guinea pig. In 30-minute local ischemia, perilymph and endolymph Ca^<2+> activities increased approximately 1.5 and 4 times as much. as the preischemic values, respectively, After the blood flow was restored, the activities decreased close to the preischemic values in an exponential manner. An evident and reversible acidification of perilymph and endolymph was also noted during local ischemia but found not so contributory to the Ca^<2+> activity changes. On the other hand, utilizing compartment models and mathematical estimations, it was disclosed that Ca^<2+> transitions could be mostly explained by passive diffusion driven by electrochemical gradients. In this analytical procedure, the apparent permeability surface area product (PS product) of blood-perilymph barrier (BPB) for Ca^<2+> was assumed slightly larger than that of blood-brain barrier (BBB), and the perilymph turnover rate was computed to be about l.4mu l/min.

Report

(4 results)
  • 1998 Annual Research Report   Final Research Report Summary
  • 1997 Annual Research Report
  • 1996 Annual Research Report
  • Research Products

    (5 results)

All Other

All Publications (5 results)

  • [Publications] 伊東善哉,他: "内耳局所虚血および呼吸性アシドーシス下における蝸牛内液pHの変化とカルシウムイオンの関係について" Otology Japan. 7(4). 268 (1997)

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      1998 Final Research Report Summary
  • [Publications] Ito Z,et al: "Changes of pH and calcium ion in the cochlear fluids under local ischemia and respiratory acidosis (Japanese)" Otology Japan. 7 (4). 268 (1997)

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      1998 Final Research Report Summary
  • [Publications] Ito Z,et al: "Analysis of calcium ion transitions in the cochlear fluids under cochlear blood flow disturbance : Mathematical demonstration based on experimental data" To be contributed to Hear Res.

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      1998 Final Research Report Summary
  • [Publications] 伊東善哉,他: "内耳局所虚血および呼吸性アシドーシス下における蝸牛内液pHの変化とカルシウムイオンの関係について" Otology Japan. 7・4. 268 (1997)

    • Related Report
      1998 Annual Research Report
  • [Publications] 伊東 善哉: "内耳局所虚血および呼吸性アシドーシス下における蝸牛内液pHの変化とカルシウムイオンの関係について" Otology Japan. 7・4. 268 (1997)

    • Related Report
      1997 Annual Research Report

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Published: 1996-04-01   Modified: 2016-04-21  

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