Fetal liver cell conditioned media as a source of erythropoietic stimulating activities.

The mechanism of erythropoietin biosynthesis is thought to be controlled by the availability of oxygen to the erythropoietin producing cell(s). Fetal liver has been shown to be a source of erythropoietin and conditioned media obtained from fetal liver cell cultures possess an erythropoietic stimulating activity. Fetal liver cultures established under lowered oxygen tensions produce and release elevated levels of erythropoietic stimulating activity while hyperoxic culture conditions result in reduced erythropoietic stimulating activity. Significant erythropoietic activity was also demonstrated from fetal liver primary and first and second passage cultures, thus extending the length of erythropoietic stimulating activity production to about 8 weeks of culture. Fetal liver cell conditioned media was also subjected to wheat germ lectin affinity chromatography to separate the erythropoietic activity from an inhibitory substance to erythroid colony formation. The inhibitory-free erythropoietic activity was eluted with n acetyl-D-glucosamine.