Attenuation of cocaine-induced locomotor activity in male and female mice by active immunization.

BACKGROUND AND OBJECTIVES: Immunotherapy for drug addiction is being investigated in several laboratories but most studies are conducted in animals of one sex. Yet, women show heightened immune responses and are more likely to develop autoimmune diseases than men. The purpose of this study was to compare the effects of an active anti-cocaine vaccine, succinyl-norcocaine conjugated to keyhole limpet hemocyanin, for its ability to elicit antibodies and alter cocaine-induced ambulatory activity in male versus female mice.
METHODS: Male and female BALB/c mice were vaccinated (n = 44) or served as non-vaccinated controls (n = 34). Three weeks after initial vaccination, a booster was given. Ambulatory activity induced by cocaine (20 mg/kg) was assessed at 7 weeks and plasma obtained at 8 weeks to assess antibody levels.
RESULTS: High antibody titers were produced in mice of both sexes. The vaccine reduced ambulatory activity cocaine-induced but this effect was greater in female compared to male mice. DISCUSSION AND
CONCLUSIONS: The efficacy of this anti-cocaine vaccine is demonstrated in mice of both sexes but its functional consequences are greater in females than males. SCIENTIFIC SIGNIFICANCE: Results point to the importance of testing animals of both sexes in studies of immunotherapies for addiction. © American Academy of Addiction Psychiatry.