PET analysis of human dopamine receptor subtypes using 11C-SCH 23390 and 11C-raclopride

Psychopharmacology (Berl). 1987;92(3):278-84. doi: 10.1007/BF00210831.


Tracer doses of 11C-SCH 23390 and 11C-raclopride, selective D1-dopamine and D2-dopamine receptor antagonists, respectively, were injected intravenously into three healthy male volunteers and two drug-treated schizophrenic patients. Regional radioactivity in brain and plasma was followed during 1 h by positron emission tomography (PET). After injection of both ligands a high accumulation of radioactivity was observed in the dopamine-rich caudate putamen. Experiments with 11C-SCH 23390, but not 11C-raclopride, showed a conspicuous accumulation of radioactivity also in the neocortex. None of the ligands accumulated in the dopamine-poor cerebellum. Specific binding of 11C-raclopride in the putamen was reduced by more than 80% in schizophrenic patients treated with antipsychotic doses of sulpiride or cis(Z)-flupentixol decanoate. 11C-SCH 23390 binding was slightly reduced in both the cortex and the putamen after treatment with cis(Z)-flupentixol decanoate but not after sulpiride. The results indicate that clinical antipsychotic drug treatment with sulpiride and cis(Z)-flupentixol decanoate causes a substantial blockade of D2-dopamine receptors in the basal ganglia but has only a minor effect on D1-dopamine receptors.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Adult
  • Benzazepines / metabolism*
  • Brain / drug effects
  • Brain / metabolism*
  • Carbon Radioisotopes
  • Flupenthixol / analogs & derivatives
  • Flupenthixol / therapeutic use
  • Humans
  • Male
  • Middle Aged
  • Raclopride
  • Receptors, Dopamine / drug effects
  • Receptors, Dopamine / metabolism*
  • Receptors, Dopamine D1
  • Receptors, Dopamine D2
  • Salicylamides / metabolism*
  • Schizophrenia / drug therapy
  • Schizophrenia / metabolism
  • Sulpiride / therapeutic use


  • Benzazepines
  • Carbon Radioisotopes
  • Receptors, Dopamine
  • Receptors, Dopamine D1
  • Receptors, Dopamine D2
  • Salicylamides
  • flupenthixol decanoate
  • Raclopride
  • Sulpiride
  • Flupenthixol