Interaction effects of ethanol and pyrazole in laboratory rodents.

1. Interactions of pyrazole and ethanol were studied in three laboratory test procedures. They included sleeping time in mice, rotor rod balance in rats and lever pressing behaviour of rats.2. Equimolar concentrations of pyrazole and 3-methylpyrazole were compared for effects on enhancement of ethanol's activity on rotor rod holding time of rats.3. Minimally effective doses of pyrazole, the LADH inhibitor, and 3-methylpyrazole, a non-inhibitor of LADH, when administered before ethanol, resulted in an increased behavioural depression. These interaction effects are probably not caused by inhibition of LADH but rather by an increase in the direct depressant action of either one or both of the compounds.