The kinetics of oxime-induced reactivation of malathion-inhibited cholinesterase has been experimentally studied in vitro. It is shown that oximes do not restore the activity of inhibited butyrylcholinesterase. Acetylcholinesterase reactivation peak (5-mins long) was found to take place upon introduction of dipyroxime (32.5%), pralidoxime (18%), carboxyme (16%) at a concentration of 2.5 x 10(-4) mol/l or toxogonine (26%) at a concentration of 5 x 10(-4) mol/l. Toxogonine demonstrated the maximum affinity to phosphorylated enzyme, while dipyroxime is characterized by a high reactivity with respect to oxime. Significant reactivating ability of these preparations (kR -2300 mol(-1) min(-1) makes them promising solution for the treatment of malathion intoxication.
