IONOPHORE-A23187 RAISES CYCLIC-AMP LEVELS IN MACROPHAGES BY STIMULATING PROSTAGLANDIN-E FORMATION

The calcium ionophore A23187 rapidly increased cAMP in rat peritoneal macrophages. The cAMP accumulation required extracellular Ca2+ and could be inhibited by indomethacin. Determinations of prostaglandins in the incubation medium revealed that the ionophore A23187 induced a rapid release of prostaglandin E (PGE) and prostaglandin F (PGF). Synthesis of PGE and PGF occurred only in the presence of extracellular Ca2+ but was not found to depend on a translocation of Ca2+ into the cells. The data suggest a direct perturbation of the cell membrane by the ionophore A23187, leading to a release of prostaglandins which mediate an increase of cAMP. © 1978.