An attempt to assess the central action of captopril and enalaprilat.

The influence of captopril and enalaprilat on central nervous system in laboratory animals has been studied. The effects of the drugs on duration of ethanol (4 g/kg i.p.) and thiopental (70 mg/kg i.p.) induced sleep, body temperature, spontaneous locomotor activity and analgesic properties (hot plate and tail-flick test) have been investigated in mice. Captopril (5 and 20 mg/kg i.p.) and enalaprilat (5 and 20 mg/kg i.p.) were used in single administration or repeated one for 10 days. Moreover, pharmaco-EEG profile of captopril and enalaprilat in rabbits has been studied. We have shown that single administration of captopril (both doses) and single or prolonged administration of enalaprilat decreased the duration of ethanol and thiopental-induced sleep. Captopril (5 mg/kg) and enalaprilat (5 and 20 mg/kg) increased pain threshold. Both studied drugs after their single or repeated administration did not influence spontaneous locomotor activity in mice. Captopril and enalaprilat decrease body temperature in mice. Examined ACEIs produce changes in EEG recording, more profoundly exhibited after administration of enalaprilat.