Authors: AnneKristine Meinild Lundby Stefanie Keiser Christoph Siebenmann Leonhard Schäffer Carsten Lundby
Publish Date: 2014/02/15
Volume: 114, Issue: 6, Pages: 1107-1111
Abstract
Erythropoietin EPO is mainly synthesized within renal peritubular fibroblasts and also other tissues such as the liver possess the ability However to what extent nonkidney produced EPO contributes to the hypoxiainduced increase in circulating EPO in adult humans remains unclearWe aimed to quantify this by assessing the distribution of EPO glycoforms which are characterized by posttranslational glycosylation patterns specific to the synthesizing cell The analysis was performed on samples obtained in seven healthy volunteers before during and after 1 month of sojourn at 3454 m altitudeUmbilical cord UC plasma served as control As expected a peak p 005 in urine 23 ± 05fold and plasma 33 ± 05fold EPO was observed on day 1 of highaltitude exposure and thereafter the concentration decreased for the urine sample obtained after 26 days at altitude but remained elevated p 005 by 15 ± 02fold above the initial sea level value for the plasma sample The EPO glycoform heterogeneity in the urine samples collected at altitude did not differ from values at sea level but were markedly lower p 005 than the mean percent migrated isoform PMI for the umbilical cord samplesOur studies demonstrate 1 UC samples express a different glycoform distribution as compared to adult humans and hence illustrates the ability to synthesis EPO in nonkidney cells during fetal development 2 as expected hypoxia augments circulating EPO in adults and the predominant source here for remains being kidney derived
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