Augmentation of DNA synthesis in guinea pig bone marrow cells by platelet-activating factor (PAF)

When guinea pig bone marrow cells were incubated in the presence of 10(-7) to 10(-5) M platelet-activating factor (PAF) for 24 to 72 hours, [3H]thymidine incorporation of cells was time-dependently augmented. The enantiomer of PAF and lysoPAF, a major metabolite of PAF, did not show significant enhancement. A non-metabolizable potent PAF agonist, 1-O-octadecyl-2-O-(N,N-dimethylcarbamoyl)-sn-glycero-3-phospholine, enhanced the [3H]thymidine incorporation at 10(-10) to 10(-8) M. This augmentation of DNA synthesis in bone marrow cells was abolished by specific PAF antagonists, CV-6209 or FR-900452. When the conditioned medium of PAF-stimulated bone marrow cells was added to another culture of bone marrow cells, the augmentation of DNA synthesis was also observed. These results suggest that PAF may affect the proliferation of one or some classes of guinea pig bone marrow cells through release of soluble factor(s).