Comparative pharmacokinetics and distribution of human urinary erythropoietin and recombinant human erythropoietin in rats.

Comparative pharmacokinetic and distribution studies of human recombinant erythropoietin (rh-EPO, Epoch, CAS 11096-26-7) and human urinary erythropoietin (u-EPO) were performed in rats. The pharmacokinetic parameters following intravenous administration of rh-EPO were similar to those of u-EPO. With respect to the concentrations of radioactivity in the liver reflecting uptakes of asialoglycoprotein, there were no differences in the concentrations between 125I-rh-EPO and 125I-u-EPO. The concentrations of radioactivity in the target organs, i.e., bone marrow and spleen in rats given 125I-rh-EPO were very similar to those of rats given 125I-u-EPO. These facts are most likely to reflect the similarity in pharmacological action.