Effect of picrotoxinin on benzodiazepine receptor binding.

The effect of picrotoxinin on [3H]flunitrazepam binding to benzodiazepine receptors was investigated. In mouse forebrain membranes, picrotoxinin inhibited basal, GABA- and pentobarbital-stimulated [3H]flunitrazepam binding; this inhibitory activity was temperature- and chloride ion-dependent. Scatchard analysis of the data indicates that picrotoxinin decreases the number of binding sites without altering binding affinity. In cerebellar membranes, picrotoxinin did not alter [3H]flunitrazepam receptor binding.