Erythropoietin and its mode of action.

摘要: Erythropoietin (Epo) is an unambiguous inducer of red cell differentiation in mammals. Purified Epo, derived from urine anemic patients, a glycoprotein molecular weight about 34,000. There are two forms with the same biological activity and amino acid composition but differing carbohydrate compositions. All form N-linked complex oligosaccharides. appears to contain three domains, protease-resistant regions containing all carbohydrate, connected by protease-sensitive region active site. Cells mice infected anemia variant Friend leukemia, bind Epo specifically. The receptors have dissociation constant 5 nM there only 600-700 per cell. has rapid effect on transcription processing globin genes. Among enzymes heme synthesis, it early uroporphyrinogen synthase. Studies colony-stimulating factor (CSF) suggest that these inducers compete for same, or very closely related cells hemopoietic system. When marrow put into close apposition centrifugation, their responses CSF competitive actions increase.