Cochlear blood flow increases after systemic hemodilution: Comparison of simultaneous laser doppler flowmetry and radioactive microsphere measurements

Alfred L. Nuttall, Elisabeth Hultcrantz, Hans Christian Larsen, Clarence Angelborg

Research output: Contribution to journalArticle

28 Scopus citations


Guinea pig cochlear blood flow was measured before and after systemic normovolemic hemodilution with high molecular weight dextran. Absolute determinations of blood flow (in the cochlea, brain, kidney and lung) were accomplished by use of radioactive-labeled (85Sr or 141Ce) microspheres. Relative measurements of the cochlear blood flow changes were made simultaneously by the use of a laser Doppler flowmeter. The flowmeter probe was placed on the first cochlear turn. Hemodilution to an average systemic hematocrit of 20% increased cochlear blood flow by 250% as measured with microspheres. The laser Doppler instrument significantly underestimated the actual flow increase giving an indication of 148%. Furthermore, the data, when analyzed on an individual trial basis, showed a very poor correlation between the two methods. The theoretical basis for these findings in relation to the use of the laser Doppler instrument is discussed.

Original languageEnglish (US)
Pages (from-to)215-223
Number of pages9
JournalHearing Research
Issue number3
StatePublished - Aug 1988



  • Cochlear blood flow
  • Dextran
  • Guinea pig
  • Hemodilution
  • Laser Doppler flowmetry
  • Radioactive microsphere

ASJC Scopus subject areas

  • Sensory Systems

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