Paraoxon increases the rate of synthesis of acetylcholinesterase in cultured muscle.

Acetylcholinesterase (AChE) activity of cultured chick embryonic pectoral muscle was significantly increased above control activity during recovery from brief treatments with paraoxon (O, O-diethyl-p-nitrophenyl phosphate), the anticholinesterase metabolite of parathion. Paraoxon also increased the rate of degradation of the enzyme, suggesting the higher AChE activity of paraoxon-treated cells was due to a stimulation of enzyme synthesis.