ISOMERIC SELECTIVITY AT DOPAMINE-D(3) RECEPTORS

Racemic 7-hydroxy-N,N-dipropylaminotetralin (7-OH-DPAT) shows greater affinity for limbic-selective dopamine D3 receptors than for more ubiq uitous dopamine D2 receptors. R(+)-7-OH-DPAT was prepared and evaluate d in radioreceptor assays using membranes of fibroblasts expressing th e human dopamine D3 receptor as well as rat striatal membranes contain ing dopamine D2. receptors. This enantiomer had 2-fold greater D3 affi nity than the racemate and similarly greater D3 vs. D2 selectivity (64 -fold). The results may facilitate development of D3 selective agents and evaluation of functions of these receptors.