The in vitro production of erythropoietin and thrombopoietin.

In order to determine if there were any relationships between thrombopoietin, erythropoietin and erythrogenin, supernatant fluids from culture lines of foetal mouse liver, foetal and adult bovine kidney, and adult rabbit kidney cells have been assayed for their content of the presumptive humoral regulators of haematopoiesis. Hormone production varied markedly from one culture line to another confirming other studies that the optimal culture conditions for the generation of haematologically-active hormones have not been delineated. The lack of any discernable relationship between the production of thrombopoietin and erythropoietin, thrombopoietin and erythrogenin or erythropoietin and erythrogenin suggests that these materials represent three distinct entities.