TY - JOUR
T1 - Cochlear blood flow increases after systemic hemodilution
T2 - Comparison of simultaneous laser doppler flowmetry and radioactive microsphere measurements
AU - Nuttall, Alfred L.
AU - Hultcrantz, Elisabeth
AU - Larsen, Hans Christian
AU - Angelborg, Clarence
N1 - Funding Information:
This work was supported by Public Health Service NIH Program Project (NS-05785) and NIH individual Grant (NS-11731) and Swedish Medical Research Council (MFR-04782). The authors wish to thank J. Nadine Brown, Michelle Griffiths and Birgitta Janson for technical support. They also acknowledge the gift of fentanyl used in the parts of this study done in the U.S.A. from Jans-sen Pharmaceutics, Inc. and the use of a periflux laser Doppler flowmeter in Sweden loaned by Perimed, AB.
PY - 1988/8
Y1 - 1988/8
N2 - 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.
AB - 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.
KW - Cochlear blood flow
KW - Dextran
KW - Guinea pig
KW - Hemodilution
KW - Laser Doppler flowmetry
KW - Radioactive microsphere
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U2 - 10.1016/0378-5955(88)90001-9
DO - 10.1016/0378-5955(88)90001-9
M3 - Article
C2 - 2459097
AN - SCOPUS:0023734845
SN - 0378-5955
VL - 34
SP - 215
EP - 223
JO - Hearing Research
JF - Hearing Research
IS - 3
ER -