The benzodiazepine receptor of mammalian brain.

There exists a saturable, high-affinity, stereospecific, regionally and pharmacologically specific, neuronally localized benzodiazepine receptor in mammalian brain, which has a development profile similar to other neurotransmitter receptors. This receptor appears to be modulated by gamma-aminobutyric acid and selected divalent cations, and chloride ions increase the affinity of the receptor for benzodiazepines. Several benzodiazepines were shown to bind irreversibly to the receptor upon exposure to ultraviolet light and these agents can be used to facilitate solubilization and purification of the benzodiazepine receptor. Although several substances have been suggested to be the endogenous ligand, none has achieved the acceptance given to other neurotransmitters or neuromodulators, e.g., enkephalins and endorphins.