Stimulation by hydrogen peroxide of L-arginine metabolism to L-citrulline coupled with nitric oxide synthesis in cultured endothelial cells.
The effect of hydrogen peroxide on metabolism of L-arginine to L-citrulline in the biosynthesis of nitric oxide was investigated in bovine aortic endothelial cells. Addition of hydrogen peroxide (1-10 mM) to endothelial cells increased L-citrulline formation from L-arginine in a dose-dependent manner. Stimulation of L-citrulline formation was prevented by catalase (20 micrograms/ml), a hydrogen peroxide scavenger, but not by superoxide dismutase (SOD, 100 micrograms/ml), a superoxide anion scavenger. Pretreatment with NG-nitro-L-arginine (10(-5) M) and NG-methyl-L-arginine (10(-4) M), potent inhibitors of nitric oxide synthase, also inhibited L-citrulline formation induced by hydrogen peroxide. Moreover, hydrogen peroxide increased intracellular Ca2+ concentrations, and the removal of extracellular Ca2+ reduced the hydrogen peroxide-induced formation of L-citrulline. These findings show that hydrogen peroxide increases the intracellular Ca2+ concentration and stimulates the formation of L-citrulline from L-arginine coupled with nitric oxide synthesis in cultured endothelial cells.
Shimizu
S
S
Department of Pharmacology, School of Pharmaceutical Sciences, Showa University, Tokyo, Japan.
Saitoh
Y
Y
Yamamoto
T
T
Momose
K
K
D000818:Animals; D001013:Aorta, Thoracic; D001120:Arginine / Q000031:analogs & derivatives / Q000378:metabolism*; D002118:Calcium / Q000378:metabolism / Q000494:pharmacology; D002374:Catalase / Q000494:pharmacology; D002417:Cattle; D002478:Cells, Cultured; D002956:Citrulline / Q000096:biosynthesis*; D004305:Dose-Response Relationship, Drug; D004730:Endothelium, Vascular / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D006861:Hydrogen Peroxide / Q000494:pharmacology*; D007770:L-Lactate Dehydrogenase / Q000378:metabolism; D009569:Nitric Oxide / Q000037:antagonists & inhibitors / Q000096:biosynthesis*; D013482:Superoxide Dismutase / Q000494:pharmacology
D002956:Citrulline; D009569:Nitric Oxide; D001120:Arginine; D006861:Hydrogen Peroxide; D007770:L-Lactate Dehydrogenase; D002374:Catalase; D013482:Superoxide Dismutase; D002118:Calcium