Intravenous self-administration of d- and l-amphetamine by dog.

The relative potency of d- and l-amphetamine to maintain i.v. self-administration behavior was studied. 5 dogs were trained to work for response-contingent drug infusions until a stable drug intake per 4 hr daily session was achieved. Then 2 unit doses of d-amphetamine (0.05 and 0.10 mg/kg/infusion) and 3 unit doses of l-amphetamine (0.20, 0.40 and 0.80 mg/kg/infusion) were evaluated in a parallel line bioassay. Each combination of drug and unit dose was examined separately for 5 consecutive daily sessions. Order of treatment presentation was determined by a Latin square design. By comparing the unit doses of d- and l-amphetamine which yielded the same rate of self-administration it was found that 1 mg of the l-isomer is equivalent to 0.17 mg of the d-isomer.