IN-VITRO REGULATION OF STROMAL FIBROBLAST PROLIFERATION BY METHYLPREDNISOLONE

The effect of methylprednisolone [MP) in the concentration 10(-7) M on cloning capacity and proliferative potential of splenic and medullary stromal fibroblast precursors was studied in hematologically normal c hildren. Medullary fibroblast culturing was performed according to A. Ya. Fridenstein method, splenic fibroblast culturing by an original pr ocedure proposed by the authors. MP stimulated proliferation of human marrow clonogenic fibroblasts more profoundly than a xenogeneic feeder could do. A successive introduction of MP and the feeder gives no ris e to synergism, while their simultaneous application induces a blockin g effect. Basing on these findings it is suggested that MP and the fee der compete for the same receptors on the adhesive cells of the explan t. Splenic fibroblasts proved sensitive to neither xenogeneic feeder n or to MP in concentration 10(-7) m.