Changes in ascorbate levels on stimulation of human neutrophils.
Changes in ascorbate levels have been measured in human neutrophils stimulated with opsonized zymosan, phorbol myristate acetate and formyl-methionyl-leucyl-phenylalanine (fMet-Leu-Phe), in the presence and absence of cytochalasin B. After stimulation with opsonized zymosan or phorbol myristate acetate, there was no loss of total ascorbate, but 30-40% of the reduced ascorbate was oxidized to dehydroascorbate. Superoxide dismutase and catalase added to the cell suspension did not inhibit this oxidation. fMet-Leu-Phe, however, gave no net oxidation but about 20% of the total ascorbate was lost during 2 h incubation. These results imply that there is not a simple relationship between superoxide and hydrogen peroxide production and ascorbate oxidation, and that release of ascorbate into the phagolysosomes does not occur.
D001205:Ascorbic Acid / Q000097:blood*; D003571:Cytochalasin B / Q000378:metabolism; D003683:Dehydroascorbic Acid / Q000097:blood; D006801:Humans; D009240:N-Formylmethionine Leucyl-Phenylalanine / Q000494:pharmacology; D009504:Neutrophils / Q000187:drug effects / Q000378:metabolism*; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology; D015054:Zymosan / Q000494:pharmacology
D003571:Cytochalasin B; D009240:N-Formylmethionine Leucyl-Phenylalanine; D015054:Zymosan; D013755:Tetradecanoylphorbol Acetate; D001205:Ascorbic Acid; D003683:Dehydroascorbic Acid