The influence of captopril and enalaprilat on central nervous system inlaboratory animals has been studied. The effects of the drugs on duration of ethanol (4 g/kg i.p.) andthiopental (70 mg/kg i.p.) induced sleep, body temperature, spontaneous locomotor activity and analgesicproperties (hot plate and tail-flick test) have been investigated in mice. Captopril (5 and 20 mg/kgi.p.) and enalaprilat (5 and 20 mg/kg i.p.) were used in single administration or repeated one for 10days. Moreover, pharmaco-EEG profile of captopril and enalaprilat in rabbits has been studied. We haveshown that single administration of captopril (both doses) and single or prolonged administration ofenalaprilat 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 administrationdid not influence spontaneous locomotor activity in mice. Captopril and enalaprilat decrease body temperaturein mice. Examined ACEIs produce changes in EEG recording, more profoundly exhibited after administrationof enalaprilat.

Keywords: Angiotensin-Converting Enzyme Inhibitors, Body Temperature, Captopril, Electroencephalography, Enalaprilat, Ethanol, Motor Activity, Pain Threshold, Sleep, Thiopental