Modulation of granulopoiesis: opposing roles of prostaglandins F and E

CSF-dependent myeloid colony growth can be augmented or inhibited by a number of modulating factors. PGs of the E series are known to inhibit colony formation. The antagonistic actions of PGE and PGF in many biological systems prompted us to compare their effects on myelopoiesis in vitro. PGF_2α at an optimal concentration of 1 × 10^-9M increased colony formation by 50% over that stimulated by CSF alone. Similar augmentation was also observed from 16,16-dimethyl PGF_2α, PGF_1α, 6-keto PGF_1α, and MIX. In contrast PGE₁, PGE₂, and 15(S),15-methyl PGE, inhibited colony growth. Simulation by PGF reflected an absolute increase in granulocytic colonies, whereas inhibition by PGE affected both granulocyte and macrophage colony formation. The relative levels of PGE and PGF may play a determining role in the modulation of granulopoiesis.