[Somatomedin C/insulin-like growth factor I and in vitro erythropoiesis]

The effect of human somatomedin C/insulin-like growth factor I(SM-C/IGF-1) and human growth hormone (hGH) on colony formation by erythroid precursor cells (CFU-E and BFU-E) from children's bone marrow or blood was studied by methylcellulose cloning assay. We found that physiological concentrations of IGF-1, but not of hGH, stimulated erythropoiesis in vitro in the presence of erythropoietin, as demonstrated by the increased activity of a cytosolic enzyme of the heme pathway (uroporphyrinogen I synthase). The results suggest that IGF-I could be involved in the regulation of erythroid differentiation.