Esterase inhibition and organophosphorus poisoning in the house-fly.

Abstract

IN a recent review paper Winteringham and Lewis1 stated that although inhibition of cholinesterase constitutes a major biochemical lesion in insects exposed to organophosphorus compounds, the importance of other lesions should not be under-estimated. Evidence of such a lesion has been found in the inhibition of other esterases. Van Asperen2 has shown that in the early stage of poisoning of house-flies treated with O,O-dimethyl-O-2, 2-dichlorovinylphosphate (DDVP) the aliphatic esterase hydrolysing methylbutyrate was inhibited by 83 per cent, whereas the inhibition of cholinesterase was only 27 per cent. He suggested that the high inhibition of the aliphatic esterase was more important than cholinesterase inhibition in organophosphorus poisoning. Hopf and Taylor3 arrived at a similar conclusion when investigating organophosphorus poisoning in the locust.