Peripheral-Type Benzodiazepine Receptors in Gliomas

Abstract

Peripheral-type benzodiazepine receptors (PBRs) are present in high concentrations in peripheral tissues of various organs, such as lung, kidney, heart, and adrenal gland, but are sparse in the normal nervous system [1]. PBRs are thought to be located on glia rather than on neurons [2]. Moreover, PBRs have been found in rodent glial tumors [3] as well as in human glial tumors, and several studies suggested that PBRs could be useful for specific imaging of glial tumors. Black et al. [4] reported that a significant correlation was observed between the high binding of PBR ligands and the degree of malignancy in gliomas in man, but Ferrarese et al. [5] reported that the binding density of PBR ligands did not correlate with malignancy. The main purpose of this study was to try to add more light to this problem by examining the concentration (Bmax) and dissociation constant (K d ) for PBRs in human gliomas.