Editorial [Hot Topic: Capabilities of PET and SPECT in Pre-Clinical and Clinical Research (Executive Editor: Michael Kassiou)]

Drug discovery and development is time consuming and a costly procedure. The challenges for pharmaceutical companies range from the evaluation of potential new drug candidates, the determination of drug pharmacokinetics/pharmacodynamics, the measurement of receptor occupancy as a determinant of drug efficacy, and the pharmacological characterisation of mechanisms of action. Radiolabelled molecules have a unique ability to monitor biochemical reactions, ligand-receptor or enzyme interactions and many other biological pathways at subnanomolar concentrations. The recent advances in computer emission tomography, image reconstruction and animal models of disease has led to the development of extremely sensitive and specific tools for imaging biochemical processes in vivo therefore representing a new means of providing information for drug development and evaluation. This issue of Current Pharmaceutical Design highlights the capabilities of PET and SPECT in preclinical and clinical research and acknowledges the efforts from each contributor in putting this issue together. John Gatley and co-workers [1] at the Brookhaven National Laboratory outlines the use of PET and SPECT in the study of human psychopharmacology. These in vivo imaging studies have been useful in conjunction with neuropsychological testing of subjects, to allow correlation of imaging data with uniquely human aspects of the effects of drugs, such as euphoria and craving. Frederic Dolle [2] at the Service Hospitaleir Frederic-Joliot outlines the recent applications of these nucleophilic heteroaromatic substitutions in the pyridine series and highlights its potential in the design and preparation, of often drug-based, fluorine-18-labelled radiotracers and radiopharmaceuticals of high specific radioactivity for PET imaging. Denis Guilloteau and Sylvie Chalon [3] at the University of Tours outline the in vivo exploration of monoamine transporters. This will enhance our knowledge of physiopathological mechanisms of brain disorders; allow early diagnosis of cerebral dysfunctions and early use of new therapies, selection of homogenous classes of subjects for therapeutic assays, objectiveness of drug-molecular target interaction, and follow-up of disease progression and treatment. Martin Pomper and co-workers [4] at the Johns Hopkins University outlines strategies relating to animal imaging and how these studies have the potential to play a major role in drug development. Most of molecular imaging research is undertaken in small animals, which provide a conduit between in vitro studies and human clinical imaging. The ability to study those animals noninvasively and quantitatively with new, high-resolution imaging devices provides the most relevant milieu in which to find and examine new therapies. References [1] Gatley SJ, Volkow ND, Wang G-J, Fowler JS, Logan J, Ding Y-S, Gerasimov M. PET Imaging in Clinical Drug Abuse Research. Curr Pharm Design 2005; (25): 3203-3219. [2] Dolle F. Fluorine-18-Labelled Fluoropyridines: Advances in Radiopharmaceutical Design. Curr Pharm Design 2005; (25): 3221-3235. [3] Guilloteau D, Chalon S. PET and SPECT Exploration of Central Monoaminergic Transporters for the Development of New Drugs and Treatments in Brain Disorders. Curr Pharm Design 2005; (25): 3237-3245. [4] Pomper MG, Lee JS. Small Animal Imaging in Drug Development. Curr Pharm Design 2005; (25): 3247-3272.