RESUMO
Plasma from hypertransfused and normal sheep and experimentally induced anemic and normal goats was fractionated by ultrafiltration. Fractions obtained were assayed for erythropoiesis stimulatory factor (ESF) or erythropoiesis inhibitory factor (EIF) activity (or both) in the posthypoxic polycythemic mouse assay. The most potent sheep plasma-inhibitor fraction was found in the retentate on a membrane with a cutoff at mol wt 50,000. The most potent EIF fraction from anemic goats passed into the ultrafiltrate, but the comparable EIF from normal goats remained in the retentate on a membrane with a cutoff at mol wt 500. The yield of the most potent EIF fraction was higher from anemic goats than was the yield from normal goats. During thin-layer chromatography, EIF extracted from goat plasma fractions had the same mobility as did prostaglandin F2 alpha. Cohn rabbit plasma fraction IV-4 had an inhibitory factor, and a benzene extract of the fraction contained a component that had the same mobility as did prostaglandin F2 alpha. Cohn rabbit plasma fraction V contained a component that potentiated an erythropoietin-generating factor.
Assuntos
Eritropoese/efeitos dos fármacos , Cabras/sangue , Plasma/metabolismo , Coelhos/sangue , Ovinos/sangue , Animais , Eritropoetina/antagonistas & inibidores , Feminino , Peso MolecularRESUMO
The bioassay for erythropoietin-stimulating factor (ESF) was compared in 3 strains of mice. One strain was made polycythemic by hypertransfusion and the other 2 by hypoxia. An erythropoiesis-generating factor (EGF) measured in the 3 strains generated approximately the same amounts of ESF, determined with log dose-log response curves for the respective techniques, after incubation with normal rabbit serum (NRS). The amount of ESF generated by EGF without prior incubation with NRS was also approximately the same in the 3 strains of mice.