The effect of selected organic solvents on intact human red cell membrane acetylcholinesterase in vitro

Human erythrocytes were exposed to different concentrations of aromatic hydrocarbons, chlorinated aliphatic hydrocarbons, and alcohols in vitro to study the effects of these agents on the activity of acetylcholinesterase (AchE), a membrane integral protein. Aromatic hydrocarbons were in general more potent AchE inhibitors than chlorinated aliphatic hydrocarbons and alcohols at +37 degrees C. The influence of decreasing the temperature to +15 degrees C and +5 degrees C was more prominent on the effect of aromatic hydrocarbons than on the effect of chlorinated aliphatic hydrocarbons and alcohols. In general, however, the decrease in the incubation temperature increased the AchE-inhibiting effect of organic solvents. The lipid solubility and molecular structure, among other factors, may determine the AchE inhibitory potency of organic solvents. Changes in membrane AchE may be one of the factors affecting membrane fluidity, which is considered to determine membrane stabilization. The primary site of action of the membrane-stabilizing agents may involve a membrane protein.