Behavioral effects of the reversible dopamine antagonist flupenthixol are not potentiated by N-ethoxycarbonyl-2-ethoxy-1,2-dihydroquinoline in the preweanling rat.

In the preweanling rat, the irreversible dopamine (DA) receptor antagonist N-ethoxycarbonyl-2-ethoxy-1,2-dihydroquinoline (EEDQ) does not diminish behaviors induced by the nonselective DA agonist R(-)-propylnorapomorphine (NPA). To determine whether EEDQ was simply inactivating an insufficient percentage of DA receptor antagonist) and/or EEDQ. When given alone, flupenthixol (0.04, 0.1, and 0.4 mg/kg, intraperitoneally [IP]) produced a dose-dependent decrease in the behavioral effects induced by 1.0 mg/kg NPA. Unexpectedly, EEDQ (7.5 mg/kg, IP) did not potentiate flupenthixol's actions. This suggests that EEDQ's inability to block the NPA-induced behaviors of preweanling rats was not the result of an insufficient percentage of DA receptors being inactivated.