Potentiation of pentazocine conditioned place preference by tripelennamine in rats

The effects of tripelennamine on place preference conditioning in rats with pentazocine were investigated. Pentazocine at a dose of 2 mg/kg (IP) slightly, but not significantly, induced a place preference. Concurrent dosing of pentazocine (2 mg/kg, IP) and tripelennamine (2.5 mg/kg, SC) significantly and prominently produced a place preference, although administration of tripelennamine (2.5 mg/kg, SC) alone did not. Chronic infusion of a dopamine D1 receptor antagonist, SCH23390 (1.0 mg/kg/day) during conditioning abolished the appetitive effect of pentazocine potentiated by the combination with tripelennamine. In conclusion, it is suggested that the dopaminergic system, especially at the D1 receptor, plays an important role in the potentiation effect of tripelennamine on the pentazocine-induced place preference.