Comparison of behavioral effects of cathinone, amphetamine and apomorphine

Rats were trained to discriminate between the stimulus properties of 0.6 mg/kg +/- -cathinone and its vehicle in a two-lever, food-motivated operant task. Once trained, rats showed a dose-related decrease in discriminative performance with lower cathinone doses and analysis of the dose-response curve indicated an ED50 of 0.24 mg/kg. Administration of 0.2-0.8 mg/kg d-amphetamine produced a pattern of responding similar to that observed with cathinone. The dose-response curve after d-amphetamine was shown to be parallel to that of cathinone and the ED50 generated was 0.21 mg/kg. Thus, cathinone was equi-potent to d-amphetamine in this behavioral paradigm. In contrast, administration of 0.16-0.32 mg/kg apomorphine produced intermediate results. The results suggest a common site and/or mechanism for action of +/- -cathinone and d-amphetamine.