A homologous series of N-alkylated cis-(+)-(1 S, 2 R)-5-methoxy-1-methyl-2-aminotetralins: central dopamine receptor antagonists showing profiles ranging from classical antagonism to selectivity for autoreceptors.
N-alkylated and N,N-dialkylated cis-(+)-(1 S, 2 R)-5-methoxy-1-methyl-2-aminotetralins were tested for central dopamine receptor antagonism using in vivo biochemical and behavioral models in rats. The di-methyl analogue showed a profile similar to classical dopamine receptor antagonists. It produced a marked hypomotility including catalepsy and a pronounced increase in dopamine synthesis rate. This compound also displaced DiPr-5, 6-ADTN from striatal binding sites and antagonized the hyperactivity induced by the ligand. In contrast, the mono-propyl analogue increased locomotor activity and dopamine synthesis rate over a wide dose range. This compound failed to antagonize the hyperactivity induced by DiPr-5, 6-ADTN and to displace this in-vivo binding ligand. Thus, the mono-propyl analogue appears to lack postsynaptic dopamine receptor antagonistic properties; it seems to produce its effects via a selective dopamine autoreceptor antagonism. The di-ethyl and di-propyl, but not the dibutyl, analogues were also active in the models used. Whereas the di-ethyl compound shows a profile similar to classical dopamine receptor blockers, the di-propyl compound appears to act preferentially on autoreceptors.
D017371:8-Hydroxy-2-(di-n-propylamino)tetralin / Q000031:analogs & derivatives*; D000818:Animals; D003342:Corpus Striatum / Q000187:drug effects / Q000378:metabolism; D004298:Dopamine / Q000096:biosynthesis; D004347:Drug Interactions; D008297:Male; D009043:Motor Activity / Q000187:drug effects; D009281:Naphthalenes / Q000494:pharmacology*; D051381:Rats; D011919:Rats, Inbred Strains; D011954:Receptors, Dopamine / Q000378:metabolism*; D013764:Tetrahydronaphthalenes / Q000494:pharmacology*
D009281:Naphthalenes; D011954:Receptors, Dopamine; D013764:Tetrahydronaphthalenes; C015842:2-(N,N-dipropyl)amino-5,6-dihydroxytetralin; D017371:8-Hydroxy-2-(di-n-propylamino)tetralin; C045971:UH 232; D004298:Dopamine