The effect of glucocorticoids on the development of murine granulocyte-macrophage (GM) progenitors.

The effect of glucocorticoids was tested on the hematopoietic system by assay of the ability of granulocyte-macrophage colony forming cells (GM-CFC) in mice to create GM colonies. The in vivo ability of bone marrow progenitor cells to granulocyte-macrophage colony formation was tested after long-term peritoneal glucocorticoids administration. The direct effect of these agents on cells in vitro culture was evaluated also. It was found that glucocorticosteroids inhibit the GM colony formation. The degree of damage to the bone marrow progenitor cells assaying by in vivo colony formation inhibition depends on the drug dosage and the length of therapy. The in vitro inhibition of granulocyte-macrophage colony formation depends on the concentration of the drug. The results suggest the possibility of the GM-CFC growth testing as an indicator of the side effects of prolonged corticoid therapy.