Improved receptor analysis in PET using a priori information from in vitro binding assays.
An accurate determination of non-specific binding is required for the analysis of in vitro and in vivo receptor binding data. For some radioligands the non-specific binding is of the same magnitude as the specific binding. Furthermore, in vitro measurements have shown that the non-specific binding can be different in different brain regions. If this is the case in a PET study for determining Bmax and Kd, a correction for the non-specific binding has to be applied. The aim of the present communication is to present a means for determining corrected Bmax and Kd with Scatchard analysis using in vitro binding studies. The influence of non-specific binding on the free and specifically bound radioligand is expressed with the aid of a correction factor, which can be calculated from measurable quantities. Introduction of the corrected free and specifically bound radioligand should give binding parameters closer to reality than previously obtained results.
Litton
J E
JE
Department of Clinical Neuroscience, Karolinska Hospital, Stockholm, Sweden. jan-eric.litton@knv.ki.se
Hall
H
H
Blomqvist
G
G
D000818:Animals; D001665:Binding Sites; D001921:Brain / Q000000981:diagnostic imaging* / Q000378:metabolism*; D006801:Humans; D007700:Kinetics; D008024:Ligands; D011869:Radioligand Assay / Q000379:methods*; D051381:Rats; D011956:Receptors, Cell Surface / Q000032:analysis* / Q000378:metabolism; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013379:Substrate Specificity; D014055:Tomography, Emission-Computed / Q000379:methods*; D015899:Tomography, Emission-Computed, Single-Photon / Q000379:methods*; D014316:Tritium
D008024:Ligands; D011956:Receptors, Cell Surface; D014316:Tritium