Sex difference in sensitization to the locomotor effects of mazindol in rats

Male and female rats were treated daily for 7 days with mazindol (5, 10, and 20 mg/kg), an anorectic drug, and tested in the open field. Mazindol developed sensitization to its locomotor stimulatory effect in both sexes on day 7 with a nondose-dependent pattern of response. However, the locomotor activity appeared to be sex dependent, female rats being more sensitive. Following a challenge dose of mazindol (10 and 20 mg/kg) on day 10, a marked enhancement of locomotion was seen in female rats. These findings indicate that repeated administration of mazindol produces sex-dependent sensitization to its effect on locomotor behavior.