DETECTION IN BLOOD AND URINE OF RECOMBINANT ERYTHROPOIETIN ADMINISTERED TO HEALTHY-MEN

A method for the detection of administered recombinant human erythropo ietin (rhEpo) in the blood and urine of healthy individuals was evalua ted. The method is based upon the observation that the electric charge of the rhEpo molecule is less negative than that of endogenous Epo. F ifteen healthy males were treated with subcutaneous injections of 20 I U rhEpo per kg body weight three times a week for 7-9 wk. The charge o f Epo in blood and concentrates of urine was determined by electrophor esis in 0.10% agarose suspension and expressed as electrophoretic mobi lity. rhEpo was detected in serum at 24 h after injection in all 15 in dividuals, at 48 h in 18 of 20 samples from II individuals, and at 72 h in 7 of 9 individuals. In urine the rhEpo was detected in all 22 sam ples taken from 11 individuals up to 24 h after injection and in 9 of 12 samples from 3 individuals at 48 h after injection. rhEpo was not d etected in serum or urine at 1-3 wk after the last injection. The char ge of both rhEpo and endogenous Epo in urine was more negative (P < 0. 001; P < 0.01) than in the paired serum samples. It is suggested that the principle of this method should be further evaluated for use in do ping control.