Formation of benzodiazepine-like molecules in rat brain.

The possible biosynthetic origin of benzodiazepine-like molecules was investigated in mammalian tissue. Rat brain homogenates or cortical slices incubated under physiological conditions showed a 4 to 7 fold increase in the content of BZD-like compounds as compared with control non incubated or boiled tissue. The quantitative analysis was performed by a radioimmunoassay with a specific monoclonal antibody. The active fraction eluting just before diazepam exhibited a Mr lower than 1300 and inhibited the [3H]flunitrazepam binding to the central benzodiazepine receptor. No activity was measured in the absence of tissue. These data suggest that under our experimental conditions, low molecular weight substances similar to benzodiazepines are formed in rat brain.