Positron emitter labeling of ligands for receptor studies

Over the past 20 years or so, the technique of positron emission tomography has undergone considerable improvement. This has been made possible by the introduction of increasingly efficient positron cameras but also by the development of increasingly rapid molecule syntheses using 11C or 18F. Of all the research possibilities afforded by this technique, ligand-receptor interaction is undoubtedly that which has attracted the most attention. After a short description of the criteria with which the ligands must comply, different molecules are suggested for the study of GABA, excitatory amino acid, adenosine, histamine, and PAF receptors, as well as molecules to visualize enzymatic systems (e.g., AchE).