Daily injections of cyanamide enhance both ethanol-induced locomotion and brain catalase activity.

A role for brain catalase in the mediation of some psychopharmacological effects of ethanol has been proposed. In the present study, we investigated the effects of repeated cyanamide injections on the activity of brain catalase, as well as on the ethanol-induced locomotion of mice. Male Swiss mice were pre-treated with cyanamide (10 mg/kg; three times per day, 5 days) or saline. At different times (2, 3, 6 or 9 days) following this treatment, animals were injected with ethanol. Immediately following this ethanol challenge, animals were placed in the open field chambers and locomotor activity was assessed for 10 min. Results indicated an increase in ethanol-induced locomotion of mice pre-treated with cyanamide 2, 3 or 6 days before the ethanol challenge. Brain catalase activity showed an enhancement at the same time period and the two variables showed a significant correlation. No differences between pre-treatment groups on ethanol blood levels were observed at time of testing. In a second study, the effects of these cyanamide treatment conditions on d-amphetamine-induced locomotor activity were assessed. Results indicated no differences between pre-treatment groups in d-amphetamine-induced locomotion. Thus, these data suggest that repeated daily injections of cyanamide can simultaneously induce both brain catalase and locomotor activity, and that these effects may be strongly related. Furthermore, the present study provides further support for the notion that brain catalase activity may be a factor mediating some of the psychopharmacological effects of ethanol.