Differential modulation of etazolate or pentobarbital enhanced [3H] muscimol binding by benzodiazepine agonists and inverse agonists.

Flunitrazepam, a benzodiazepine agonist increases, and DMCM, an inverse agonist decreases the stimulation by etazolate or pentobarbital of [3H] muscimol binding to membranes of rat cerebral cortex. Ro 15-1788 has no marked effects but antagonizes the action of both flunitrazepam and DMCM. The investigation of several drugs acting on benzodiazepine receptors on etazolate enhancement of [3H] muscimol binding suggests that their receptor interaction reflects a spectrum from agonists to inverse agonists.