Estimation of the ED50 dose required to occupy dopamine D2 and D4 receptors in the brain using in vivo [3H]SKF 10047 binding to mouse whole brain
| Compound | ED50 mg/kg Sigma Assay | 50% D2 Receptor Occupancy | 50% D4 Receptor Occupancy |
|---|---|---|---|
| L-745,870 | 3.0 | 37 mg/kg | 35 μg/kg |
| Clozapine | 8.0 | 310 μg/kg | 47 μg/kg |
| Haloperidol | 0.03 | 3.6 μg/kg | 32 μg/kg |
Mice received drug treatment 40 min before [3H]SKF 10047 5 μCi/mouse i.v. and in vivo binding was determined as described in “Methods.” The estimated 50% D2 and D4 receptor occupancy doses were calculated from a comparison of the receptor binding affinities of the drug for the sigma binding site and either the rat D2 or rat D4 dopamine receptor.