The peripheral-type benzodiazepine receptor and adrenal steroidogenesis

Abstract

Studies using biochemical and pharmacologic approaches in steroidogenic cells and subcellular fractions have shown that the peripheral-type benzodiazepine receptor (PBR) is an outer mitochondrial membrane protein involved in the regulation of cholesterol transport from the outer to the inner mitochondrial membrane, the rate-determining step in steroid biosynthesis. Recent studies using gene targeting, antisense RNA, gene expression, and mutagenesis technology have demonstrated the obligatory role of PBR in cholesterol transport. In addition, the development of in vivo models and ontogeny studies have validated data obtained in in vitro experiments, confirming the role of PBR in steroidogenesis and suggesting that the presence of PBR is an absolute prerequisite for adrenocortical function.