EXTRACTION OF ERYTHROPOIETIN FROM ISOLATED RENAL GLOMERULI OF HYPOXIC RATS

  • 1 January 1983
    • journal article
    • research article
    • Vol. 11  (7) , 581-589
Abstract
Whether erythropoietin (Ep) can be extracted from renal glomeruli of hypoxic rats was investigated. Hypoxia was induced in a hypobaric chamber at 0.42 atm for usually 6 h. Glomeruli were isolated with a sieving technique from kidneys that were flushed free of blood. Ep activities in glomeruli homogenates were determined in the fetal mouse liver cell assay and in the hypoxia exposed mouse assay. In vitro erythropoietic activity of glomerular extracts was found which increased about 25-fold during hypoxia. Incubation of the extracts with anti-Ep serum abolished the activity. Its binding characteristics on wheat germ lectin, Ricinus communis lectin and DEAE-cellulose suggested that glomeruli contained Ep precursor(s) that lacked terminal sugar residues. Such an incomplete carbohydrate portion seems also compatible with the finding that glomerular extracts did not stimulate erythropoiesis in hypoxia exposed mice.