Background: Recombinant human erythropoietin (rHuEpo) is the treatment of choice in anemia associated with end-stage renal disease. Its major side effect is hypertension, which occurs in 8-30% of uremic patients. The exact mechanism of rHuEpo-induced hypertension has not been fully elucidated, and several possibilities have been proposed, such as a direct vascular effect of the drug with a shift in the balance of constrictor and relaxing endothelial factors (endothelins and nitric oxide (NO)). Recent papers suggested an enhanced rather than reduced activity of endogenous NO system in rats with normal renal function and rHuEpo-induced hypertension. Our study was designed to verify whether, in spite of enhanced activity of the renal NO system, rHuEpo may affect endothelium-dependent (acetylcholine-induced) and/or endothelium-independent (sodium nitroprusside-induced) vasorelaxation and to evaluate basal NO release by the infusion of NG-nitro-L-arginine methyl ester (L-NAME) in an isolated and perfused rat kidney model.
Methods: To investigate this hypothesis, we have determined systemic and renal NO activity in Wistar rats treated with a hypertensive dose of rHuEpo (150 IU/kg b.w. every other day for 2 weeks) by measuring stable NO metabolites (NO2+NO3) in the urine and have also evaluated variations in renal vascular resistance after the injection of Ach, SNP and the infusion of L-NAME.
Results: Hematocrit, hemoglobin concentration and arterial blood pressure were significantly increased in the treated group as compared with the controls. Urinary excretion of NO2+NO3 was significantly higher in treated than in the controls (438+/-66 vs. 294+/-36 nM/ml/min, p<0.01, respectively). There were no significant differences in the dose-response curves to Ach and SNP between the two groups. The renal vasoconstriction following the infusion of L-NAME was also similar in the two groups.
Conclusions: The analysis of our results seems to indicate that the endogenous NO system activity was enhanced in rHuEpo-induced hypertension in rats with normal renal function and a resistance to NO was not developed in renal circulation. Further studies seem to be necessary to better clarify the exact mechanisms underlying the development of rHuEpo-induced hypertension.
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http://dx.doi.org/10.1159/000025920 | DOI Listing |
Life Sci
April 2016
Research Unit on Applied Molecular Biosciences (UCIBIO), REQUIMTE, Department of Biological Sciences, Laboratory of Biochemistry, Faculty of Pharmacy, University of Porto, Porto, Portugal. Electronic address:
Our aim was to study the effect of a broad range of recombinant human erythropoietin (rHuEPO) doses on hematological and biochemical parameters, blood pressure (BP), renal function and damage in the rat, focusing on endothelial nitric oxide synthase (eNOS) and hypoxia-inducible factors (HIFs). Male Wistar rats were divided in 5 groups receiving different doses of rHuEPO (100, 200, 400 and 600IU/kg body weight (BW)/week) and saline solution (control), during 3weeks. Blood and 24h urine were collected to perform hematological and biochemical analysis.
View Article and Find Full Text PDFClin Exp Hypertens
January 2016
Clinical Investigation Center, Pontificia Universidade Católica do Rio Grande do Sul , Porto Alegre , Brazil .
Background: Approximately 30% of the chronic kidney disease patients using recombinant human erythropoietin (rhuEPO) have an increase in blood pressure (BP). Its mechanism and whether it depends on renal function remain unclear. There is early evidence that acetylsalicylic acid (ASA) prevents the rhuEPO-induced increase in BP.
View Article and Find Full Text PDFRen Fail
July 2003
Division of Nephrology and Hypertension, Department of Medicine, Koto Hospital, Tokyo, Japan.
Regular administration of recombinant human erythropoietin (rHuEPO) is frequently associated with a rise in arterial blood pressure in hemodialysis (HD) patients. The aim of this study was to examine the effects of rHuEPO on plasma endothelin (ET)-1 and nitric oxide products (NOx) concentration in HD patients. Fifteen patients on maintenance HD with hematocrit of less than 25% were included in the present study.
View Article and Find Full Text PDFAm J Kidney Dis
October 2001
Department of Medicine, Division of Nephrology and Dialysis, University of Vienna, Vienna, Austria.
Cardiac diseases account for almost 50% of deaths in long-term dialysis patients. Left ventricular dysfunction is present in approximately 80% of these patients and is highly predictive of future ischemic heart disease, cardiac failure, and death. Anemia has been identified as one of several risk factors responsible for cardiac complications.
View Article and Find Full Text PDFInt J Artif Organs
June 2001
Medical Clinic II, Technical University Hospital, Aachen, Germany.
The correction of anemia with human recombinant erythropoietin (rHuEPO) in end stage renal disease is associated with hypertension in about one third of hemodialysis patients. The pathogenesis of the rHuEPO-induced hypertension is still uncertain, though evidence of the involvement of endothelial cells has emerged. The aim of this study was to determine plasma endothelin-1 during hemodialysis and to compare the endothelin-1 levels in hemodialysis patients with and without rHuEPO substitution.
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