N-NITROSATED N-HYDROXYGUANIDINES ARE NITRIC OXIDE-RELEASING DIAZENIUMDIOLATES

N-Hydroxyguanidines can be nitrosatively converted to zwitterionic dia zeniumdiolates of crystallographically-confirmed structure H2N+=C[NHR] [N(O)NO](-), whose hydrolytic dissociation at physiological pH leads t o both NO and N2O; the results appear to account for the formation of the 'potential intercellular nitric oxide carrier' produced on exposin g N-G-hydroxy-L-arginine (a metabolic intermediate in mammalian NO bio synthesis) to aerobic NO.