Intracellular singlet oxygen generation by phagocytosing neutrophils in response to particles coated with a chemical trap.

摘要: To determine if singlet oxygen (O2(1 delta g)) is produced by neutrophils (PMNs) during the process of phagocytosis, glass beads were coated with a specific chemical trap for O2(1 g), 9,10-diphenylanthracene (DPA). Singlet oxygen, but not other reactive species, reacts rapidly DPA at rate kr = 1.3 x 10(6) M-1 s-1 to form stable product, DPA-endoperoxide (Corey, E. J., and Taylor, W. C. (1964) J. Am. Chem. Soc. 86, 3881-3882; Wasserman, H. H., Scheffer, R., Cooper, L. (1972) 94, 4991-4996; Turro, N. Chow, M.-F., Rigaudy, (1981) 103, 7218-7224). The production was determined ultraviolet spectroscopy as decrease in absorbance 355 nm. normalized perylene, which included coating on nonreactive, internal standard. In present study, DPA- perylene-coated initially allowed adhere fibronectin-coated coverslips. PMNs then added bead-coated coverslips phagocytose 1 h 37 degrees some experiments, 4B-phorbol-12-myristate-13-acetate (PMA) (1 ng/2.5 10(7) cells/ml), known activator PMN NADPH-oxidase, co-stimulant. amount g) phagocytically stimulated calculated be 11.3 +/- 4.9 nmol g)/1.25 cells. Low dose PMA co-stimulation increased 14.1 4.1 nmol/1.25 Averaged together these amounts represent approximately 19 5.0% total consumed response beads. specificity reaction confirmed warming 120 C, releases from DPA-endoperoxide, regenerating parent compound (Wasserman et al., 1972; Turro 1981) addition, beta-carotene, an avid quencher bead preparations; assays used showed no change myeloperoxidase also measured using assay results suggest that this major pathway generated PMNs.(ABSTRACT TRUNCATED AT 400 WORDS)