A close association has been reported for certain types of cancers influenc
ed by aromatic amines and infection/inflammation. Reactive nitric oxygen sp
ecies (RNOS), components of the inflammatory response, are bactericidal and
tumoricidal, and contribute to the deleterious effects attributed to infla
mmation on normal tissues. This study assessed the possible transformation
of the aromatic amine N-acetylbenzidine (ABZ) by RNOS. RNOS were generated
by various conditions to react with ABZ, and samples were evaluated by HPLC
. Conditions which generate nitrogen dioxide radical (NO2- + myeloperoxidas
e + H2O2, ONOO-, and NO2- + HOCl) produced primarily a single new product t
ermed 3'-nitro-ABZ. The myeloperoxidase-catalyzed reaction with 0.3 mM NO2-
was completely inhibited by 1 mM cyanide, and not effected by 100 mM chlor
ide with or without 1 mM taurine. In contrast, conditions which generate N2
O3, such as spermine NONOate, did not produce 3'-nitro-ABZ, but rather two
compounds termed 4'-OH-AABP and AABP. H-1 NMR and mass spectrometry identif
ied 3'-nitro-ABZ as 3'-nitro-N-acetylbenzidine, 4'-OH-AABP as 4'-OH-4-acety
laminobiphenyl, and AABP as 4-acetylaminobiphenyl. Human polymorphonuclear
neutrophils incubated with [H-3]-ABZ and stimulated with beta -phorbol 12-m
yristate 13-acetate produced 3'-nitro-ABZ in the presence of NO2- (0.1-1 mM
). Neutrophil 3'-nitro-ABZ formation was verified by mass spectrometry and
was consistent with myeloperoxidase oxidation of NO2-. The results demonstr
ate that ABZ forms unique products in the presence of nitrosating and nitra
ting RNOS, which could influence the carcinogenic process and serve as biom
arkers for these reactive species.