Permanent URL to this publication: http://dx.doi.org/10.5167/uzh-36083
Olsen, N V; Aachmann-Andersen, N J; Oturai, P; Andersen, T M; Rasmussen, A B; Hulston, C; Holstein-Rathlou, N H; Robach, P; Lundby, C (2011). Erythropoietin down-regulates proximal renal tubular reabsorption and causes a fall in glomerular filtration rate in humans. Journal of Physiology, 589(6):1273-1281.
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rHuEPO elevates hemoglobin concentration both by increasing red blood cell volume and by a decrease in plasma volume. This study delineates the association of rHuEPO-induced changes in blood volumes with changes in the renin-aldosterone system and renal function. 16 healthy males were given rHuEPO for 28 days in doses raising the hematocrit to 48.3 (4.1) %. Renal clearance studies with urine collections (N = 8) were done at baseline and at days 4, 11, 29, and 42. Glomerular filtration rate (GFR) was measured by (51)Cr-EDTA. Renal clearance of lithium (C(Li)) was used as an index of proximal tubular outflow and to assess segmental renal tubular handling of sodium and water. rHuEPO-induced increases in hematocrit occurred from day 10 onwards and was caused by both an increase in red cell volume and a fall in plasma volume. Well before that (from day 2 and throughout the treatment time), rHuEPO decreased plasma levels of renin and aldosterone (N = 8) by 21 - 33 % (P < 0.05) and 15 - 36 % (P < 0.05), respectively. After cessation of rHuEPO values returned to baseline. On days 11 and 29 C(Li) increased (P < 0.02) indicating a significant 10 - 16 % decrease in absolute proximal reabsorption of sodium and water (APR = GFR - C(Li), P < 0.05). GFR decreased slightly, albeit significantly on day 4 (P < 0.05). In conclusion, rHuEPO promptly, and before any changes in blood volumes and hematocrit can be detected, causes a down-regulation of the renin-aldosterone system. The results are compatible with a rHuEPO-induced reduction in proximal reabsorption rate leading to activation of the tubuloglomerular feedback mechanism and a fall in GFR. By this, treatment with rHuEPO may result in suppression of endogenous EPO synthesis secondary to a decrease in intrarenal oxygen consumption.
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|Item Type:||Journal Article, refereed, original work|
|Communities & Collections:||04 Faculty of Medicine > Center for Integrative Human Physiology
04 Faculty of Medicine > Institute of Physiology
07 Faculty of Science > Institute of Physiology
|DDC:||570 Life sciences; biology
610 Medicine & health
|Deposited On:||12 Nov 2010 15:12|
|Last Modified:||28 Nov 2013 01:40|
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