Dopamine D2 receptors selectively labeled by a benzamide neuroleptic: [3H]-YM-09151-2

H. B. Niznik, D. E. Grigoriadis, I. Pri-Bar, O. Buchman, P. Seeman

Research output: Contribution to journalArticlepeer-review

103 Scopus citations


In order to label dopamine D2 receptors selectively we tritiated the potent benzamide neuroleptic, YM-09151-2 (26.7 Ci/mmol). The binding of [3H]-YM-09151-2 to canine striatal membranes was saturable and specific with a KD of 57 pmol/l and Bmax of 36 pmol/g tissue as determined by Scatchard analysis. The KD, but not the Bmax, of [3H]-YM-09151-2 increased 6-fold in the absence of sodium chloride. [3H]-YM-09151-2 labeled 40% more sites than [3H]-spiperone in the same tissue homogenate. [3H]-YM-09151-2 binding was inhibited by dopaminergic drugs in a concentration and stereoselective manner with the appropriate dopamine D2 receptor profile. Thus, dopamine agonists inhibited [3H]-YM-09151-2 binding to canine striatal membranes with the following rank order of potency: (-)-N-n-propylnorapomorphine > apomorphine > (±)-6,7-dihydroxy-2-aminotetralin > (+)-N-n-propylnorapomorphine > dopamine > (-)-noradrenaline > serotonin > (-)-isoprenaline. Dopaminergic antagonists competed for [3H]-YM-09151-2 binding with the following order of potency: spiperone > (+)-butaclamol > haloperidol > clebopride > (-)-sulpiride > SCH-23390 > (-)-butaclamol. Furthermore, dopamine agonists recognized 2 states of the receptor labeled by [3H]-YM-09151-2, D2highand D2low. The D2highstate of the receptor could be converted to D2lowby guanine nucleotides and sodium ions as is the case for [3H]-spiperone binding to D2 receptors. [3H]-YM-09151-2 appears to be a more selective ligand for dopamine D2 receptors than [3H]-spiperone, since YM-09151-2 displays approximately 9-fold lower affinity than spiperone for cortical serotonergic (S2) receptors. [3H]-YM-09151-2 may become a useful tool for the selective characterization of dopamine D2 receptors.

Original languageEnglish
Pages (from-to)333-343
Number of pages11
JournalNaunyn-Schmiedeberg's Archives of Pharmacology
Issue number4
StatePublished - 1 Jun 1985
Externally publishedYes


  • Benzamide neuroleptics
  • Dopamine D receptors
  • Labeling
  • [H]-Spiperone
  • [H]-YM-09151-2

ASJC Scopus subject areas

  • Pharmacology


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