Activity of an NADPH-dependent nitroreductase in houseflies

A nitroreductase, reducing parathion to aminoparathion, was found in the soluble fraction that was obtained from abdomens of female houseflies. The reaction required reduced nicotinamide adenine dinucleotide phosphate (NADPH), but was not affected by the presence or absence of oxygen. Further degradation of aminoparathion into water-soluble compounds occurred in NADPH-fortified incubation mixtures over prolonged incubation periods. The effect of sesamex or SKF 525-A on these reactions is described.