Evaluation of deprenyl for cocaine-like discriminative stimulus effects in rats

The antiparkinsonian agent l-deprenyl is metabolized to l-methamphetamine and l-amphetamine and, at higher doses, can facilitate the release and inhibit the reuptake of dopamine. Since l-deprenyl can affect dopamine release and reuptake it was important to evaluate it for cocaine-like discriminative stimulus effects. Male Fisher rats were trained to discriminate cocaine (10 mg/kg, i.p.) from saline in a two-lever, operant-conditioning procedure using schedules of food-delivery or stimulus-shock termination. l-Deprenyl (17 mg/kg, i.p.) produced full generalization to cocaine under the food-delivery schedule but this or higher doses produced only partial generalization to cocaine under the stimulus-shock termination schedule. d-Deprenyl produced full generalization to cocaine under both schedules at i.p. doses of 5.6 to 10 mg/kg. These cocaine-like discriminative stimulus effects occur only at doses that are well above the clinically relevant dose range for l-deprenyl.