Long-term treatment with haloperidol or clozapine does not affect dopamine D4 receptors in rat frontal cortex.
We examined the effects of long-term treatment with haloperidol and clozapine on dopamine D4 receptors in rat frontal cortex. Dopamine D4 receptor binding sites were indirectly determined from the displacement experiments of [3H]clozapine binding using nemonapride. Three-weeks administration of haloperidol (0.5 mg/kg) or clozapine (10 mg/kg) did not significantly affect the D4 receptors in the frontal cortex. The density of D2 receptors, determined by [3H]spiperone binding to striatum, was increased by long-term treatment with haloperidol, but it was not significantly changed by that with clozapine.
Kusumi
I
I
Department of Psychiatry, Hokkaido University School of Medicine, Sapporo, Japan.
Ishikane
T
T
Matsubara
S
S
Koyama
T
T
D000818:Animals; D014150:Antipsychotic Agents / Q000493:pharmacokinetics / Q000494:pharmacology*; D003024:Clozapine / Q000493:pharmacokinetics / Q000494:pharmacology*; D018492:Dopamine Antagonists / Q000493:pharmacokinetics / Q000494:pharmacology*; D004334:Drug Administration Schedule; D006220:Haloperidol / Q000493:pharmacokinetics / Q000494:pharmacology*; D008297:Male; D017397:Prefrontal Cortex / Q000187:drug effects* / Q000378:metabolism*; D051381:Rats; D017208:Rats, Wistar; D017448:Receptors, Dopamine D2 / Q000187:drug effects* / Q000378:metabolism; D050638:Receptors, Dopamine D4
D014150:Antipsychotic Agents; D018492:Dopamine Antagonists; C493601:Drd4 protein, rat; D017448:Receptors, Dopamine D2; D050638:Receptors, Dopamine D4; D003024:Clozapine; D006220:Haloperidol