Popis: |
1. 1. The effects of prostaglandin (PG) E1, and I2 analogs (OP-41483 and OP-2507) on the Superoxide generation of human neutrophil NADPH oxidase (EC 1.6.99.6) in both whole-cell and cell-free systems were investigated. 2. 2. In a whole-cell system, OP-2507 inhibited the Superoxide generation by neutrophils exposed to phorbol myristate acetate concentration-dependently through its superoxide-scavenging action. 3. 3. The concentration of the drug required for 50% inhibition of the oxidase (IC50) was 21 μM. 4. 4. In a cell-free system, however, the drug in concentrations of < 100 μM did not inhibit the activation of NADPH oxidase by sodium dodecyl sulfate because of its inactivation by the detergent. 5. 5. Although PGE1 and OP-41483 did not inhibit the Superoxide production by stimulated neutrophils in a whole-cell system, they both inhibited the activation of NADPH oxidase in a cell-free system concentration-dependently, with IC50 values of 44 and 170 μM, respectively. 6. 6. In addition, in the cell-free system, the Km value for NADPH of the oxidase was unchanged by PGE1. 7. 7. The results suggest that the PGI2 analog, OP-2507, is a possible superoxide-scavenger and that PGE1 inhibits the NADPH oxidase activation by sodium dodecyl sulfate in a cell-free system concentration-dependently. |