Extracellular ATP triggers superoxide production in human neutrophils.
The effects of ATP on the concentration of cytosolic calcium [( Ca2+]i) were examined with respect to early events associated with activation of the superoxide (O2-)-generating system in human neutrophils. Addition of ATP to cytochalasin B-treated neutrophils resulted in two sequential increase in [Ca2+]i: an initial phase presumably related to the mobilization of Ca2+ from intracellular stores and a second phase dependent upon the presence of extracellular Ca2+. The second phase was associated with an increase in the rate of O2- production, which also required the presence of extracellular Ca2+. The results suggest that increased Ca2+ influx may act to trigger a cascade of Ca2+-sensitive events, leading to stimulated O2-production.
Kuroki
M
M
Department of Biochemistry, Kyushu University School of Medicine, Fukuoka, Japan.
Minakami
S
S
D000255:Adenosine Triphosphate / Q000494:pharmacology*; D001572:Benzofurans; D002118:Calcium / Q000097:blood; D003571:Cytochalasin B; D005110:Extracellular Space / Q000187:drug effects / Q000502:physiology; D005456:Fluorescent Dyes; D016257:Fura-2 / Q000031:analogs & derivatives*; D006801:Humans; D007700:Kinetics; D009504:Neutrophils / Q000187:drug effects / Q000378:metabolism*; D013481:Superoxides / Q000096:biosynthesis* / Q000097:blood
D001572:Benzofurans; D005456:Fluorescent Dyes; C049925:fura-2-am; D013481:Superoxides; D003571:Cytochalasin B; D000255:Adenosine Triphosphate; D002118:Calcium; D016257:Fura-2