An inhibitor of cyclic AMP-dependent protein kinase enhances the superoxide production of human neutrophils stimulated by N-formyl-methionyl-leucyl-phenylalanine.
Intact human neutrophils produced superoxide (O2-) by the stimulation with N-formyl-methionyl-leucyl-phenylalanine (fMLP) even when the extracellular Ca2+ was absent (0.56 +/- 0.13 nmol/min per 10(6) cells). The production by fMLP was enhanced more than twice in the presence of the extracellular Ca2+. Moreover, the O2- production by fMLP in the presence of extracellular Ca2+ was enhanced nearly three times by the treatment of cells with H-89, an inhibitor of cyclic AMP-dependent protein kinase (PKA). The enhancement was not observed when the extracellular Ca2+ was depleted from the reaction mixture. In addition, H-89 did not enhance fMLP-induced O2- production of electropermeabilized neutrophils in which the intracellular Ca2+ concentration was fixed to about 100 nM. These observations suggest that not only Ca2+ influx but the inhibition of PKA is necessary for the maximum O2- production by fMLP and that the O2- production is partially suppressed by the activation of PKA induced by fMLP.
Mitsuyama
T
T
Research Institute for Diseases of the Chest, Kyushu University School of Medicine, Fukuoka, Japan.
Takeshige
K
K
Furuno
T
T
Tanaka
T
T
Hidaka
K
K
Abe
M
M
Hara
N
N
D003994:Bucladesine / Q000494:pharmacology; D002118:Calcium / Q000378:metabolism; D002463:Cell Membrane Permeability; D000242:Cyclic AMP / Q000494:pharmacology; D017868:Cyclic AMP-Dependent Protein Kinases / Q000037:antagonists & inhibitors*; D004305:Dose-Response Relationship, Drug; D005260:Female; D006801:Humans; D066298:In Vitro Techniques; D007546:Isoquinolines / Q000494:pharmacology*; D008297:Male; D009240:N-Formylmethionine Leucyl-Phenylalanine / Q000494:pharmacology; D018375:Neutrophil Activation; D009504:Neutrophils / Q000378:metabolism*; D016897:Respiratory Burst; D015398:Signal Transduction; D012967:Sodium Dodecyl Sulfate / Q000494:pharmacology; D013449:Sulfonamides; D013481:Superoxides / Q000378:metabolism*; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology
D007546:Isoquinolines; D013449:Sulfonamides; D013481:Superoxides; D012967:Sodium Dodecyl Sulfate; D009240:N-Formylmethionine Leucyl-Phenylalanine; D003994:Bucladesine; D000242:Cyclic AMP; D017868:Cyclic AMP-Dependent Protein Kinases; C063509:N-(2-(4-bromocinnamylamino)ethyl)-5-isoquinolinesulfonamide; D013755:Tetradecanoylphorbol Acetate; D002118:Calcium