The effect of acetylsalicylic acid/salicylic acid mixtures on acetylcholinesterase activity in vitro.

An attempt was made to inhibit acetylcholinesterase activity in homogenates of rat brain and in 2% solutions of hemolyzed human or rat erythrocytes, with concentrations of acetylsalicylic acid/salicylic acid (ASA/SA) equivalent to those evident in human plasma 0--2 h after ingestion of 0.65 g of ASA. None of the 5 different ASA/SA mixtures used produced inhibition in any of the enzyme preparations while the reference compound, eserine, inhibited all. These results suggest that ingestion of ASA, at least in recommended doses, should not significantly influence acetylcholinesterase activity in vivo.