Specificity of the suppressive action of glucocorticoids on the proliferation of monocyte/macrophages in the CSF-stimulated cultures of mouse bone marrow.

ABSTRACT

Addition of cortisol and its analogs to soft-agar culture of bone marrow cells markedly decreased the number of monocyte colonies in the presence of colony-stimulating factor. Steroids of other categories and cortisol metabolites were much less inhibitory than cortisol, and the shape of dose-response curve apparently differed between cortisol and other steroids. The action of cortisol was not influenced by excess progesterone or testosterone. Addition of cortisol succinate in liquid cultures of CSF-stimulated cells caused a gradual decrease of cellular uptake of [3H]thymidine. The steroid also suppressed CSF-independent [3H]thymidine uptake, but the time course of suppression obviously differed from that of CSF-dependent uptake. On day 7 of incubation, the steroid-treated cultures contained a smaller number of cells but higher activities of lysosomal enzymes than the control cultures. These results show that the glucocorticoids inhibit proliferation of the cells of monocyte/macrophage lineage.