In vivo measurement of glucose utilization in rats using a beta-microprobe: direct comparison with autoradiography.
A new beta-microprobe (betaP) has been used to locally measure the time-concentration curve of a radiolabeled substance. The betaP, analogous to positron emission tomography methodology, is useful for in vivo animal studies because it can acquire time-concentration curves with high temporal and spatial resolution. Using [18F]fluoro-2-deoxy-D-glucose and betaP, we evaluated the reliability of the biologic parameters and we compared this method with the [14C]2-deoxy-D-glucose autoradiography. BetaP time-concentration curves in three regions of the brain were obtained from 24 rats. Four kinetic parameters (K1-k4) were estimated from 60-minute experimental periods using a three-compartment model. Best fits were obtained when the vascular fraction (Fv) was estimated simultaneously with the four kinetic parameters (K1-k4). The mean estimated Fv values were about 5.5% for the frontal cortex regions and 8.0% for the cerebellum. Correlation coefficients higher than 0.830 were observed between regional cerebral metabolic rates for glucose (rCMRglc) values obtained by betaP and autoradiography. In addition, the betaP-derived input function was similar to that obtained by manual sampling. Our findings show that reliable rCMRglc values can be obtained using betaP.
Millet
Philippe
P
Unité de Neuroimagerie, Service de Neuropsychiatrie, Hôpitaux Universitaires de Genève, Chêne-Bourg, Switzerland. Philippe.Millet@sim.hcuge.ch
Sallanon
Marcelle Moulin
MM
Petit
Jean-Marie
JM
Charnay
Yves
Y
Vallet
Philippe
P
Morel
Christian
C
Cespuglio
Raymond
R
Magistretti
Pierre J
PJ
Ibáñez
Vicente
V
D000818:Animals; D001345:Autoradiography; D001921:Brain / Q000378:metabolism*; D002250:Carbon Radioisotopes / Q000378:metabolism; D003847:Deoxyglucose / Q000378:metabolism*; D003952:Diagnostic Imaging / Q000379:methods*; D004305:Dose-Response Relationship, Drug; D005462:Fluorine Radioisotopes / Q000378:metabolism; D019788:Fluorodeoxyglucose F18 / Q000378:metabolism; D005947:Glucose / Q000378:metabolism*; D008297:Male; D008959:Models, Neurological; D051381:Rats; D017207:Rats, Sprague-Dawley; D013997:Time Factors
D002250:Carbon Radioisotopes; D005462:Fluorine Radioisotopes; D019788:Fluorodeoxyglucose F18; D003847:Deoxyglucose; D005947:Glucose