Benzodiazepine receptors: effect of tissue preincubation at 37 degrees C.

[3H]Flunitrazepam binding to rat brain homogenates was assayed in two ways: by 37-0 degrees C incubations or 0 degrees C only incubations. The affinity of brain benzodiazepine receptors for [3H]flunitrazepam was significantly greater in 37-0 degrees C incubated samples than in 0 degrees C incubated samples, while there was no change in the number of benzodiazepine receptors. The possible mechanisms for this enhanced binding affinity as well as the methodological implications for this observation are discussed.