[Peripheral benzodiazepine receptors and their possible biological role]

While specific BZD receptors in the central nervous system were identified using [3H]diazepam as radioligand, additional binding sites have been found also in peripheral tissues. These so-called "peripheral-type benzodiazepine receptors" occur ubiquitous in various tissues. Different actions on biological processes have been described to be connected with peripheral-type benzodiazepine receptors, but their definite physiological role has not yet been clarified. this review covers basic findings of this second binding site for benzodiazepines, trying to present a survey about those binding sites and their putative biological role.