In Vivo biological activities of recombinant human erythropoietin analogues produced by CHO cells, BHK cells and C127 cells

Abstract

The in vivo biological activity of four pharmaceutical preparations of recombinant human erythropoietin was compared. Two of the erythropoietins were produced by Chinese hamster ovary cells, CHO-K1, and the others were produced by mouse mammary cells, C127, and baby hamster kidney cells, BHK-21. The activities of the analogues were estimated by a simple cell counting method with conventional automated microcell counters. 23,24 The amounts of these analogues gave straight logarithmic dose-response curves when plotted against the count of particles resistant to hemolysing reagent, which particles were mostly immature reticulocytes. The lines from the four analogues were parallel to each other. The relative activities of these analogues were 1·02, 1·19 and 1·21 when one of the analogues was arbitrarily used as the standard. These differences in the extent of the activity were not significant. Thus, the four recombinant human erythropoietin analogues, produced by four different mammalian cell lines, expressed the same biological potencies in vivo corresponding to their units, and the units used up to now by the manufacturers are equivalent. These results also draw the conclusion that the new simple in vivo bioassay can replace the existing accepted assay methods.