Studies on the action of chlordimeform in cockroaches

The effects of chlordimeform N-(2-methyl-4-chlorophenyl)-N′,N′-dimethylformamidine] on amine regulatory mechanisms in insects were studied. Chlordimeform inhibits monoamine oxidase (MAO) from cockroach heads in vitro, and the MAO substrates serotonin and norepinephrine accumulate in poisoned insects in vivo. Chlordimeform synergizes the toxicity of tryptamine, another MAO substrate. The significance of these findings in relation to the mode of action of chlordimeform is discussed.