A novel nonenzymatic pathway for the generation of nitric oxide by the reaction of hydrogen peroxide and D- or L-arginine.
Nitric oxide (NO) is a biologically active molecule known to be enzymatically synthesized from L-arginine in the presence of NO synthetase (NOS). In this study, we demonstrate a novel non-enzymatic pathway for NO synthesis involving hydrogen peroxide and D- or L-arginine. We employed two measures of NO generation. The first consists in the demonstration of the oxidative metabolites of NO (NO2 + NO3 = NOx) and the second is the confirmatory finding of chemiluminescence derived from NO. The results show that NOx increases in the incubation mixture containing hydrogen peroxide coupled with D-arginine, L-arginine, L-canavanine, and even the NOS inhibitor N(G)-nitro-L-arginine methyl ester (L-NAME). However, chemiluminescence was detected only from the reactions of hydrogen peroxide and D- or L-arginine and was diminished by the addition of carboxy-2-phenyl-4, 4,5,5-tetramethyl-imidazoline-1-oxyl-3-oxide (PTIO), a specific scavenger of NO, confirming NO generation in the reaction.
Nagase
S
S
Department of Internal Medicine, Institute of Clinical Medicine, University of Tsukuba, Ibaraki, Japan. sohji-n@md.tsukuba.ac.jp
Takemura
K
K
Ueda
A
A
Hirayama
A
A
Aoyagi
K
K
Kondoh
M
M
Koyama
A
A
D000596:Amino Acids / Q000032:analysis; D001120:Arginine / Q000737:chemistry*; D006861:Hydrogen Peroxide / Q000737:chemistry*; D008163:Luminescent Measurements; D009566:Nitrates / Q000032:analysis; D009569:Nitric Oxide / Q000138:chemical synthesis*; D009573:Nitrites / Q000032:analysis
D000596:Amino Acids; D009566:Nitrates; D009573:Nitrites; D009569:Nitric Oxide; D001120:Arginine; D006861:Hydrogen Peroxide