The inhibitory effects of some iodonium compounds on the superoxide generating system of neutrophils and their failure to inhibit diaphorase activity.

I have recently reported the inhibition of the neutrophil superoxide generating oxidase by very low concentrations of diphenylene iodonium (A. R. Cross and O. T. G. Jones, Biochem. J. 237, 111, 1986). Here I report on the sensitivity of the oxidase to two other iodonium compounds, iodonium thiophen and iodonium biphenyl. In addition, the lack of inhibition of dye reductase activity in a solubilized preparation of the oxidase is described suggesting that the superoxide forming enzyme system of neutrophils does not possess an intrinsic dye reductase activity.