Phenazepam in therapeutic and ultralow doses in vitro modulates the content of lipid peroxidation products and acetylcholinesterase activity in membrane fraction from mouse brain.

In vitro incorporation of tranquilizer phenazepam in a concentration of 10(-13) M into membrane fraction from mouse brain produced a prooxidant effect. In concentrations of 10(-5)-10(-9) and 10(-15)-10(-17) M this agent possessed antioxidant activity. Phenazepam significantly decreased the maximum rate of enzymatic reactions (10(-5) and 10(-15) M) and Michaelis constant (10(-5) M) for acetylcholinesterase. Incorporation of phenazepam in ultralow doses into membrane modified its lipid components (estimated by lipid peroxidation) and functional state, and this effect was comparable with the influence of this substance in standard doses. This probably contributes to the physiological effect of ultralow doses of phenazepam in.