Bradykinin induces generation of reactive oxygen species in bovine aortic endothelial cells.
We investigated the effects of bradykinin on intracellular oxidative stress in bovine aortic endothelial cells using a hydroperoxide-sensitive fluorescent dye, 2',7'-dichlorofluorescein (DCFH), and a laser scanning confocal microscope. Bradykinin induced an immediate increase in intracellular Ca2+ concentration, and stimulated the oxidation of DCFH in cultured endothelial cells. This bradykinin-induced oxidation of DCFH was inhibited by pretreatment with N-(2-mercaptopropionyl)-glycine (MPG) and 1,3-dimethyl-thiourea (DMTU), scavengers of hydroxyl radical, and the removal of extracellular Ca2+ but was unaffected by NG-nitro-L-arginine or NG-monomethyl-L-arginine, both inhibitors of nitric oxide (NO) synthase. On the other hand, pretreatment with indomethacin and aspirin, inhibitors of cyclooxygenase, inhibited bradykinin-induced oxidation of DCFH. These findings suggest that bradykinin increases intracellular Ca2+ and stimulates the generation of hydroxyl radical-like reactive oxygen species (scavenged by MPG or DMTU) via the cyclooxygenase pathway but not via the reaction of NO and superoxide anion.
Shimizu
S
S
Department of Pharmacology, School of Pharmaceutical Sciences, Showa University, Tokyo, Japan.
Ishii
M
M
Yamamoto
T
T
Kawanishi
T
T
Momose
K
K
Kuroiwa
Y
Y
D000594:Amino Acid Oxidoreductases / Q000037:antagonists & inhibitors; D000818:Animals; D001011:Aorta; D001920:Bradykinin / Q000037:antagonists & inhibitors / Q000494:pharmacology*; D002118:Calcium / Q000378:metabolism; D002417:Cattle; D002478:Cells, Cultured; D016861:Cyclooxygenase Inhibitors / Q000494:pharmacology; D004730:Endothelium, Vascular / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D005452:Fluoresceins / Q000378:metabolism; D016166:Free Radical Scavengers; D017665:Hydroxyl Radical / Q000378:metabolism; D008856:Microscopy, Fluorescence; D019001:Nitric Oxide Synthase; D018384:Oxidative Stress / Q000187:drug effects; D017382:Reactive Oxygen Species / Q000378:metabolism*
D016861:Cyclooxygenase Inhibitors; D005452:Fluoresceins; D016166:Free Radical Scavengers; D017382:Reactive Oxygen Species; D017665:Hydroxyl Radical; C037631:2',7'-dichlorofluorescein; D019001:Nitric Oxide Synthase; D000594:Amino Acid Oxidoreductases; D001920:Bradykinin; D002118:Calcium