Receptor affinities of aporphine enantiomers in rat brain tissue.
R(-) and S(+) enantiomers of apomorphine, N-n-propylnorapomorphine and 11-hydroxy-N-n-propylnorapomorphine were screened for affinity at over 40 representative sites in rat brain tissue that included amine, purine, amino acid and peptide receptors, transporters, ion channels, and effector components; only dopamine receptors and alpha-adrenoceptors showed appreciable affinity that was quantified further. The aporphines showed R(-) > S(+) isomeric selectivity as well as D2 > D1 selectivity at dopamine receptors. While R(-) isomers preferred alpha 2-adrenoceptors, S(+)-aporphines were alpha 1-selective, with similar affinity at alpha 1-adrenoceptors and dopamine D2 receptors. Interactions of S(+)-aporphines at alpha 1-adrenoceptors as well as dopamine D2 receptors may contribute to their unusual behavioral properties.
Baldessarini
R J
RJ
Consolidated Department of Psychiatry, Harvard Medical School, Boston, MA.
Kula
N S
NS
Zong
R
R
Neumeyer
J L
JL
D000818:Animals; D001058:Apomorphine / Q000031:analogs & derivatives / Q000493:pharmacokinetics; D001060:Aporphines / Q000493:pharmacokinetics*; D001921:Brain / Q000378:metabolism*; D015259:Dopamine Agents / Q000493:pharmacokinetics; D066298:In Vitro Techniques; D008297:Male; D051381:Rats; D017207:Rats, Sprague-Dawley; D011956:Receptors, Cell Surface / Q000378:metabolism*; D017981:Receptors, Neurotransmitter / Q000378:metabolism; D013237:Stereoisomerism
D001060:Aporphines; D015259:Dopamine Agents; D011956:Receptors, Cell Surface; D017981:Receptors, Neurotransmitter; C009074:N-n-propylnorapomorphine; C008081:11-hydroxy-N-(n-propyl)noraporphine; D001058:Apomorphine