Table II.
Radioligand | Nonspecific binding | Tissue | K i | |
---|---|---|---|---|
Sigma receptors | ||||
σ 1 | 5 nM [3H](+)-pentazocine | 10 μM haloperidol | Rat brain | 2.4 ± 0.63 |
σ 2 | 3 nM [3H]di-o-tolylguanidine | 10 μM haloperidol | Rat brain | 0.51 ± 0.15 |
Monoamine transporters | ||||
Dopamine | 0.5 nM [3H]WIN 35,428 | 50 μM cocaine | Rat striatum | 872 ± 122 |
Serotonin | 0.2 nM [3H]paroxetine | 1.5 μM imipramine | Rat brainstem | 612 ± 44 |
Norepinephrine | 0.5 nM [3H]nisoxetine | 4 μM desipramine | Rat cerebral cortex | >10,000 |
Non-sigma sites | ||||
Opioid | 1 nM [3H]naloxone | 1 μM naloxone | Rat brain | >10,000 |
5-HT2 | 2 nM [3H]ketanserin | 1 μM mianserin | Rat brain | 535 ± 51 |
Dopamine (D2) | 5 nM [3H](−)-sulpiride | 1 μM haloperidol | Rat brain | 1183 ± 272 |
NMDA/PCP | 5 nM [3H]TCP | 10 μM cyclazocine | Rat brain | >10,000 |
Affinities (K i in nanomolars) were determined in rat brain. The values in this table represent the mean ± SEM from replicate assays
NMDA N-methyl-d-aspartic acid, PCP phencyclidine, TCP tenocyclidine