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Measurement of transferrin receptor kinetics in the baboon liver using dynamic positron emission tomography imaging and [ 18 F]holo‐transferrin
Author(s) -
Aloj L,
Carson R E,
Lang L,
Herscovitch P,
Eckelman W C
Publication year - 1997
Publication title -
hepatology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 5.488
H-Index - 361
eISSN - 1527-3350
pISSN - 0270-9139
DOI - 10.1002/hep.510250432
Subject(s) - transferrin , baboon , positron emission tomography , spleen , in vivo , pharmacokinetics , biodistribution , transferrin receptor , chemistry , compartment (ship) , nuclear medicine , pathology , pharmacology , medicine , endocrinology , biology , biochemistry , oceanography , microbiology and biotechnology , geology
We have evaluated the use of [ 18 F]holo‐transferrin ([ 18 F]Tf) and positron emission tomography (PET) to measure in vivo Tf receptor expression and recycling using the baboon liver as a model. [ 18 F]Tf was intravenously injected in three baboons and dynamic PET was performed over the region containing liver and spleen. In two of the three baboons, [ 18 F]albumin ([ 18 F]Alb), labeled with the same technique, was administered 3 hours later. Time activity curves (TACs) were obtained from liver and spleen for both tracers. TACs for [ 18 F]Tf over the liver were fit to a pharmacokinetic model including vascular radioactivity and an extravascular tissue compartment corresponding to transferrin uptake and release. [ 18 F]Alb data provided an independent estimate of plasma volume. Kinetic analysis showed the presence of a tissue compartment for [ 18 F]Tf that rapidly reaches equilibrium (half time 7‐10 minutes). In this organ, the measured rates for Tf turnover obtained with quantitative PET are similar to previously published data using cell culture systems. A model for [ 18 F]Tf in the spleen was not statistically improved by adding a tissue compartment. These data and the pharmacokinetic modeling provide in vivo evidence of a high flux equilibrium binding compartment in the liver, consistent with Tf internalization and recycling.