PHOTOAFFINITY-LABELING OF THE BENZODIAZEPINE RECEPTOR IN BOVINE CEREBRAL-CORTEX

Clonazepam, nitrazepam and flunitrazepam were found to engage in an irreversible interaction with benzodiazepine binding sites in bovine cerebral cortex homogenates upon irradiation with ultraviolet light. Photoaffinity labeling with [3H]flunitrazepam could be substantially (approx. 85%) inhibited by a number of different benzodiazepines, including clonazepam, lorazepam, Ro5-3027, and non-radioactive flunitrazepam. Spiroperidol, atropine, naltrexone, propranolol and GABA had no effect on irreversible [3H]flunitrazepam binding, indicating that this binding is to the benzodiazepine receptor as defined in previous studies. © 1979.