title: Hepatic erythropoietin: enhanced production in anephric rats with hyperplasia of Kupffer cells.
abstract: Erythropoietin (Ep) levels were assayed in serum of adult male rats subjected sequentially to (1) administration of colloidal carbon, Zymosan or their vehicles (2) sham operation or bilateral nephrectomy with and without subtotal hepatictomy, and (3) hypoxia (0.45-0.40 atmospheres of air for 6 h starting 1 h after the operation). In anephric rats these agents induced a significant potentiation of hypoxic Ep activity. Since they did not apparently modify the kinetics of exogenous Ep, it is postulated that this phenomenon is mediated by enhanced extrarenal Ep production. Both colloidal carbon and Zymosan induced hyperplasia of the reticuloendothelial system (RES). Moreover, subtotal hepatectomy almost abolished the Ep response to hypoxia evoked by Zymosan. The correlation between hyperplasia of hepatic RES and enhanced Ep production in anephric rats primed with these agents suggests that Kupffer cells constitute a major source for extrarenal Ep. Additionally, it is of interest that colloidal carbon and Zymosan did not significantly modify the renal production of Ep.
mesh_terms: D000818:Animals; D002244:Carbon; D004921:Erythropoietin / Q000096:biosynthesis*; D000860:Hypoxia / Q000378:metabolism; D007668:Kidney / Q000378:metabolism; D007728:Kupffer Cells / Q000378:metabolism*; D008099:Liver / Q000378:metabolism*; D008297:Male; D009392:Nephrectomy; D051381:Rats; D015054:Zymosan
chemical_list: D004921:Erythropoietin; D002244:Carbon; D015054:Zymosan