abstract
- The effect of hydrocortisone on the formation of erythroid colonies was studied in vitro in cultures of normal human bone marrow in an agar system. A range of concentrations of hydrocortisone (10(-10) to 10(-3) mol/l) showed significant effects on erythroid burst formation, in terms of the number of colonies, on d 10 and 14 of culture. At subphysiological concentrations (10(-10) to 10(-8) mol/l), no effect was seen, but at both physiological (10(-7) mol/l) and pharmacological (10(-6) and 10(-5) mol/l) concentrations stimulation of erythroid burst formation was noted. At 10(-4) mol/l hydrocortisone inhibited erythroid colony formation and 10(-3) mol/l was uniformly lethal. In the concentration range of 10(-7) to 10(-5) mol/l hydrocortisone also appeared to increase erythroid colony size. Thus hydrocortisone (10(-7) to 10(-5) mol/l) stimulates erythroid colony growth and it is suggested that the hormone may play a role in the physiological regulation of human erythropoiesis.