Abstract
Methods are described for the separation of nondialyzable material with erythropoietic activity (urinary hemopoietine), from urine of rabbits made anemic (< 5g Hb/100) by phenylhydrazine and of patients with aplastic anemia (< 5g Hb/100). The material obtained was assayed for its effects on Fe59 distribution 3 and 24 hours after tracer injection. The active extracts produced a marked increase in the rate of Fe59 clearance from plasma, and in the fraction of the injected Fe59 appearing in erythrocytes at 3 and 24 hours. Effect of the extracts was seen to be a linear function of log dose. The extracts prepared from urine of patients with aplastic anemia had a specific activity about 3 times higher than that obtained from urine of phenylhydrazine rabbits. The fractions of highest specific activity obtained from rabbit’s urine were (a) that precipitating between 50-75 per cent ethanol at pH 4.5; (b) adsorbed by kaolin at pH 4.5 and eluted at pH 7-8; and (c) adsorbed by D.E.A.E. cellulose at pH 4.5 and eluted by 0.2 M Na2HPO4 in 0.5 M. NaC1. Only the ethanol procedure was used for human urine, and it was seen that specific activities of the 0-50 and 50-75 per cent fractions were similar.
The fractions obtained from human and rabbit urine showed great variability in hexose, sialic acid and hexosamine contents, and no clear correlation was apparent between gross chemical composition and erythropoietic activity. Paper electrophoresis showed the presence of a single component moving behind albumin, in both active and inactive extracts of human urine.
