The dopamine D-3 receptor antagonist, (+)-S 14297, blocks the cataleptic properties of haloperidol in rats

In contrast to haloperidol, the selective dopamine D-3 receptor antagonist, (+)-S 11566 {(+/-)-[7-(N,N-dipropylamino)-5,6,7,8-tetrahydro-naphtho(2,3b) dihydro,2,3-furane]} and its active isomer, (+/-)-S 14297, induced neither catalepsy nor reduced conditioned avoidance responses in rats. (+)-S 11566 and (+)-S 14297 did, however, dose-dependently abolish the cataleptic actions of haloperidol. This action was expressed stereospecifically inasmuch as (-)-S 17777, the inactive distomer of (+)-S 14297, was ineffective. Further, the influence of haloperidol upon conditioned avoidance responses was not affected by (+)-S 14297. These data suggest that blockade of dopamine D, receptors may inhibit the extrapyramidal but not - as based on the conditioned avoidance response paradigm - antipsychotic actions of neuroleptics. (C) 1997 Elsevier Science B.V. All rights reserved.