Regulation of erythropoiesis

The regulation of erythropoiesis is an important factor in maintaining normal blood viscosity. In this short summary the three erythroid compartments in the bone marrow are described: the stem cells, the committed cells and the morphologically recognisable cells. The stimulating factors burst forming activity (BFA) and erythropoietin (Ep) act on the committed cells. The production of Ep is regulated through tissue oxygenation while BFA seems to be unrelated to this. Under normal conditions erythropoiesis is a well regulated system, while under pathological conditions it may escape control and thus give rise to very high haematocrits and increased blood viscosity.