Rg. Booth et al., ACTIONS OF (+ -)-7-HYDROXY-N,N-DIPROPYLAMINOTETRALIN (7-OH-DPAT) ON DOPAMINE SYNTHESIS IN LIMBIC AND EXTRAPYRAMIDAL REGIONS OF RAT-BRAIN/, Brain research, 662(1-2), 1994, pp. 283-288
The proposed D-3-selective ligand (+/-)-7-hydroxy-N,N-dipropylaminotet
ralin (7-OH-DPAT) inhibited tyrosine hydroxylase in vitro (IC50 = 0.6-
0.7 mu M) and dihydroxyphenylalanine (DOPA) accumulation in vivo (ID50
= 4.8-6.4 mg/kg) in two autoreceptor models in extrapyramidal and lim
bic tissue in rat forebrain, without consistent regional selectivity.
Some limbic selectivity (ID50 = 10 vs. 29 mg/kg) was found in an in vi
vo model permitting expression of postsynaptic D-3 and D-2 receptor ac
tivity. The effects were partially blocked by S(-)-eticlopride alone,
and fury after reserpine pretreatment. The results suggest that 7-OH-D
PAT activates D-3 or D-2 autoreceptors, alters dopamine storage or rel
ease, and may interact with some limbic selectivity at postsynaptic D-
3 and D-2 receptors as a partial agonist.