Characteristics of beta-phenethylamine self-administration by dog.

Phenethylamine (PEA), a biologically active amine found in the brain, maintained intravenous self-administration behavior by dogs previously trained to respond for amphetamine. Systematic changes in the unit dose of PEA (1.5 to 6.0 mg/kg/infusion) were negatively related to the number of infusions (91.3 to 29.5, respectively) per 4hr session. The mean intake of PEA was 165 mg/kg/session. Pretreatment with chlorpromazine (0.5 to 2.0 mg/kg, IV, 30 min prior to the session) produced a dose-dependent increase in the number of self-administered PEA infusions. However, there were no changes in responding for PEA following pretreatment with either the dopaminergic antagonist pimozide (5 to 40 micrograms/kg, IV, 30 min prior to the session) or the adrenergic antagonist phenoxybenzamine (1 to 8 mg/kg, IV, 30 min prior to the session). These data suggest that the reinforcing properties of PEA are not dependent on either a dopaminergic or adrenergic system.