Prostaglandin D2 Modulates Human Neutrophil Intracellular Calcium Flux and Inhibits Superoxide Release via Its Ring Carbonyl.

摘要

We compared the effects of prostaglandin D2 (PGD2), prostaglandin F2 alpha (PGF2 alpha) and various ketones on O2- release by human neutrophils, which had been stimulated by N-formyl methionyl leucyl phenylalanine (FMLP). Our data suggests that the ring carbonyl of PGD2 is essential to its inhibitory effect on O2- release, but the carbonyl group as a ketone, alone, is not sufficient. Using the fluorescent Ca(2+) probe, Fura-2AM, we found that PGD2 decreased the late phase of FMLP invoked changes in intracellular free CA(2+) (Ca)i, but that PGF2 alpha had no effect. Since cAMP altered FMLP stimulated (Ca)i in a pattern similar to PGD2, we suggest that PGD2 inhibits O2- release by increasing intracellular cAMP which in turn causes an increase in the rate of decline in (Ca)i. Furthermore, the ring carbonyl of PGD2 is crucial to its effect on O2- as well as on (Ca)i. Keywords: Calcium, Cations, Superoxides. (aw)