The effect of chronic in vivo infusion of forskolin on noradrenergic receptor sensitivity

The study of in vivo occupancy of benzodiazepine receptors in rat hippocampus and cerebellum indicates that premazepam reaches only about 70% and 80% occupancy respectively within the dose range used for pharmacological tests in rats. Moreover, at equiactive doses (antileptazol ED₅₀), more brain receptors are occupied by premazepam than by other benzodiazepines, suggesting that premazepam may act as a partial agonist at benzodiazepine receptors, with intrinsic activity lower in cerebellum than in hippocampus. These results may explain the lack of sedative and ataxic properties of premazepam.