ELECTROSPRAY MASS-SPECTROMETRIC, SPECTROPHOTOMETRIC AND ELECTROCHEMICAL METHODS DO NOT PROVIDE EVIDENCE FOR THE BINDING OF NITRIC-OXIDE BY PYOCYANINE AT PH-7

In several recent publications on pyocyanine, its mechanism of action has been attributed to an ability to react with nitric oxide (NO), res ulting in the formation of an adduct. We examined the chemical interac tion of pyocyanine and NO using electrospray (ES) MS, spectrophotometr y and voltammetry at neutral pH and with 10-100 mu M pyocyanine. No bi nding of NO to pyocyanine was observed. Alternative mechanisms for the inhibition of NO-induced vasorelaxation of pyocyanine should be sough t.