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Barbieri M, Chiodini P, Di Gennaro P, Hafez G, Liabeuf S, Malyszko J, Mani LY, Mattace-Raso F, Pepin M, Perico N, Simeoni M, Zoccali C, Tortorella G, Capuano A, Remuzzi G, Capasso G, Paolisso G. Efficacy of erythropoietin as a neuroprotective agent in CKD-associated cognitive dysfunction: A literature systematic review. Pharmacol Res 2024; 203:107146. [PMID: 38493928 DOI: 10.1016/j.phrs.2024.107146] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/09/2024] [Revised: 03/15/2024] [Accepted: 03/15/2024] [Indexed: 03/19/2024]
Abstract
Patients with chronic kidney disease (CKD) often experience mild cognitive impairment and other neurocognitive disorders. Studies have shown that erythropoietin (EPO) and its receptor have neuroprotective effects in cell and animal models of nervous system disorders. Recombinant human EPO (rHuEPO), commonly used to treat anemia in CKD patients, could be a neuroprotective agent. In this systematic review, we aimed to assess the published studies investigating the cognitive benefits of rHuEPO treatment in individuals with reduced kidney function. We comprehensively searched Pubmed, Cochrane Library, Scopus, and Web of Science databases from 1990 to 2023. After selection, 24 studies were analyzed, considering study design, sample size, participant characteristics, intervention, and main findings. The collective results of these studies in CKD patients indicated that rHuEPO enhances brain function, improves performance on neuropsychological tests, and positively affects electroencephalography measurements. These findings suggest that rHuEPO could be a promising neuroprotective agent for managing CKD-related cognitive impairment.
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Affiliation(s)
- Michelangela Barbieri
- Department of Advanced Medical and Surgical Sciences, University of Campania "Luigi Vanvitelli", Naples, Italy.
| | - Paolo Chiodini
- Medical Statistics Unit, University of Campania "Luigi Vanvitelli", Caserta 81100, Italy
| | - Piergiacomo Di Gennaro
- Medical Statistics Unit, University of Campania "Luigi Vanvitelli", Caserta 81100, Italy
| | - Gaye Hafez
- Department of Pharmacology, Faculty of Pharmacy, Altinbas University, Istanbul, Turkey
| | - Sophie Liabeuf
- Pharmacoepidemiology Unit, Department of Clinical Pharmacology, Amiens University Medical Center, Amiens, France; MP3CV Laboratory, EA7517, Jules Verne University of Picardie, Amiens, France
| | - Jolanta Malyszko
- Department of Nephrology, Dialysis and Internal Medicine, Medical University of Warsaw, Warsaw, Poland
| | - Laila-Yasmin Mani
- Department of Nephrology and Hypertension, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland
| | - Francesco Mattace-Raso
- Department of Internal Medicine, Section of Geriatric Medicine, Erasmus MC, University Medical Center Rotterdam, the Netherlands
| | - Marion Pepin
- Clinical Epidemiology, CESP, INSERM, UMR 1018, Paris Saclay University, Villejuif, France; Department of Geriatrics, Ambroise Paré University Medical Center, APHP, Boulogne-Billancourt, France
| | - Norberto Perico
- Istituto di Ricerche Farmacologiche Mario Negri, Bergamo, Italy
| | - Mariadelina Simeoni
- Department of Translational Medical Sciences, University of Campania Luigi Vanvitelli, Naples, Italy
| | - Carmine Zoccali
- Renal Research Institute, New York, USA; Institute of Biology and Molecular Biology (BIOGEM), Ariano Irpino, Italy; IPNET, Reggio Calabria, Italy
| | - Giovanni Tortorella
- Department of Advanced Medical and Surgical Sciences, University of Campania "Luigi Vanvitelli", Naples, Italy
| | - Annalisa Capuano
- Section of Pharmacology 'L. Donatelli', Department of Experimental Medicine, University of Campania 'Luigi Vanvitelli', Campania Regional Centre for Pharmacovigilance and Pharmacoepidemiology, Naples, Italy
| | | | | | - Giuseppe Paolisso
- Department of Advanced Medical and Surgical Sciences, University of Campania "Luigi Vanvitelli", Naples, Italy; UniCamillus, International Medical University, Rome, Italy
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Fourteen days of smoking cessation improves muscle fatigue resistance and reverses markers of systemic inflammation. Sci Rep 2021; 11:12286. [PMID: 34112815 PMCID: PMC8192509 DOI: 10.1038/s41598-021-91510-x] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2021] [Accepted: 05/20/2021] [Indexed: 02/05/2023] Open
Abstract
Cigarette smoking has a negative effect on respiratory and skeletal muscle function and is a risk factor for various chronic diseases. To assess the effects of 14 days of smoking cessation on respiratory and skeletal muscle function, markers of inflammation and oxidative stress in humans. Spirometry, skeletal muscle function, circulating carboxyhaemoglobin levels, advanced glycation end products (AGEs), markers of oxidative stress and serum cytokines were measured in 38 non-smokers, and in 48 cigarette smokers at baseline and after 14 days of smoking cessation. Peak expiratory flow (p = 0.004) and forced expiratory volume in 1 s/forced vital capacity (p = 0.037) were lower in smokers compared to non-smokers but did not change significantly after smoking cessation. Smoking cessation increased skeletal muscle fatigue resistance (p < 0.001). Haemoglobin content, haematocrit, carboxyhaemoglobin, total AGEs, malondialdehyde, TNF-α, IL-2, IL-4, IL-6 and IL-10 (p < 0.05) levels were higher, and total antioxidant status (TAS), IL-12p70 and eosinophil numbers were lower (p < 0.05) in smokers. IL-4, IL-6, IL-10 and IL-12p70 had returned towards levels seen in non-smokers after 14 days smoking cessation (p < 0.05), and IL-2 and TNF-α showed a similar pattern but had not yet fully returned to levels seen in non-smokers. Haemoglobin, haematocrit, eosinophil count, AGEs, MDA and TAS did not significantly change with smoking cessation. Two weeks of smoking cessation was accompanied with an improved muscle fatigue resistance and a reduction in low-grade systemic inflammation in smokers.
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Haider T, Diaz V, Albert J, Alvarez-Sanchez M, Thiersch M, Maggiorini M, Hilty MP, Spengler CM, Gassmann M. A Single 60.000 IU Dose of Erythropoietin Does Not Improve Short-Term Aerobic Exercise Performance in Healthy Subjects: A Randomized, Double-Blind, Placebo-Controlled Crossover Trial. Front Physiol 2020; 11:537389. [PMID: 33117187 PMCID: PMC7550763 DOI: 10.3389/fphys.2020.537389] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2020] [Accepted: 08/26/2020] [Indexed: 01/13/2023] Open
Abstract
Erythropoietin (EPO) boosts exercise performance through increase in oxygen transport capacity following regular administration of EPO but preclinical study results suggest that single high dose of EPO also may improve exercise capacity. Twenty-nine healthy subjects (14 males/15 females; age: 25 ± 3 years) were included in a randomized, double-blind, placebo-controlled crossover study to assess peak work load and cardiopulmonary variables during submaximal and maximal cycling tests following a single dose of 60.000 IU of recombinant erythropoietin (EPO) or placebo (PLA). Submaximal exercise at 40%/60% of peak work load revealed no main effect of EPO on oxygen uptake (27.9 ± 8.7 ml min–1⋅kg–1/ 37.1 ± 13.2 ml min–1⋅kg–1) versus PLA (25.2 ± 3.7 ml min–1⋅kg–1/ 33.1 ± 5.3 ml min–1⋅kg–1) condition (p = 0.447/p = 0.756). During maximal exercise peak work load (PLA: 3.5 ± 0.6 W⋅kg–1 vs. EPO: 3.5 ± 0.6 W kg–1, p = 0.892) and peak oxygen uptake (PLA: 45.1 ± 10.4 ml⋅min–1 kg–1 vs. EPO: 46.1 ± 14.2 ml⋅min–1 kg–1, p = 0.344) reached comparable values in the two treatment conditions. Other cardiopulmonary variables (ventilation, cardiac output, heart rate) also reached similar levels in the two treatment conditions. An interaction effect was found between treatment condition and sex resulting in higher peak oxygen consumption (p = 0.048) and ventilation (p = 0.044) in EPO-treated males. In conclusion, in a carefully conducted study using placebo-controlled design the present data failed to support the hypothesis that a single high dose of EPO has a measurable impact on work capacity in healthy subjects.
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Affiliation(s)
- Thomas Haider
- Institute for Veterinary Physiology, Vetsuisse Faculty, University of Zurich, Zurich, Switzerland.,Zurich Center for Integrative Human Physiology (ZIHP), Zurich, Switzerland.,Department of Cardiology, University Hospital Zürich, Zurich, Switzerland
| | - Victor Diaz
- Institute for Veterinary Physiology, Vetsuisse Faculty, University of Zurich, Zurich, Switzerland
| | - Jamie Albert
- Institute of Human Movement Science and Sport, ETH Zürich, Zurich, Switzerland
| | - Maria Alvarez-Sanchez
- Institute for Veterinary Physiology, Vetsuisse Faculty, University of Zurich, Zurich, Switzerland
| | - Markus Thiersch
- Institute for Veterinary Physiology, Vetsuisse Faculty, University of Zurich, Zurich, Switzerland
| | - Marco Maggiorini
- Institute of Intensive Care Medicine, University Hospital of Zürich, Zurich, Switzerland
| | - Matthias P Hilty
- Institute of Intensive Care Medicine, University Hospital of Zürich, Zurich, Switzerland
| | - Christina M Spengler
- Zurich Center for Integrative Human Physiology (ZIHP), Zurich, Switzerland.,Institute of Human Movement Science and Sport, ETH Zürich, Zurich, Switzerland
| | - Max Gassmann
- Institute for Veterinary Physiology, Vetsuisse Faculty, University of Zurich, Zurich, Switzerland.,Zurich Center for Integrative Human Physiology (ZIHP), Zurich, Switzerland
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Pugh J, Pugh C. Neurostimulation, doping, and the spirit of sport. NEUROETHICS-NETH 2020; 14:141-158. [PMID: 34824648 PMCID: PMC8590673 DOI: 10.1007/s12152-020-09435-7] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2019] [Accepted: 04/27/2020] [Indexed: 12/19/2022]
Abstract
There is increasing interest in using neuro-stimulation devices to achieve an ergogenic effect in elite athletes. Although the World Anti-Doping Authority (WADA) does not currently prohibit neuro-stimulation techniques, a number of researchers have called on WADA to consider its position on this issue. Focusing on trans-cranial direct current stimulation (tDCS) as a case study of an imminent so-called ‘neuro-doping’ intervention, we argue that the emerging evidence suggests that tDCS may meet WADA’s own criteria (pertaining to safety, performance-enhancing effect, and incompatibility with the ‘spirit of sport’) for a method’s inclusion on its list of prohibited substances and methods. We begin by surveying WADA’s general approach to doping, and highlight important limitations to the current evidence base regarding the performance-enhancing effect of pharmacological doping substances. We then review the current evidence base for the safety and efficacy of tDCS, and argue that despite significant shortcomings, there may be sufficient evidence for WADA to consider prohibiting tDCS, in light of the comparable flaws in the evidence base for pharmacological doping substances. In the second half of the paper, we argue that the question of whether WADA ought to ban tDCS turns significantly on the question of whether it is compatible with the ‘spirit of sport’ criterion. We critique some of the previously published positions on this, and advocate our own sport-specific and application-specific approach. Despite these arguments, we finally conclude by suggesting that tDCS ought to be monitored rather than prohibited due to compelling non-ideal considerations.
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Affiliation(s)
- Jonathan Pugh
- The Oxford Uehiro Centre for Practical Ethics, University of Oxford, Suite 8, Littlegate House, St Ebbes Street, Oxford, OX1 1PT UK
| | - Christopher Pugh
- Cardiff School of Sport and Health Sciences, Cardiff Metropolitan University, Cardiff, UK
- Cardiff Centre for Exercise and Health, Cardiff Metropolitan University, Cardiff, UK
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Trinh KV, Diep D, Chen KJQ, Huang L, Gulenko O. Effect of erythropoietin on athletic performance: a systematic review and meta-analysis. BMJ Open Sport Exerc Med 2020; 6:e000716. [PMID: 32411382 PMCID: PMC7213874 DOI: 10.1136/bmjsem-2019-000716] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/06/2020] [Indexed: 12/15/2022] Open
Abstract
Introduction Athletes have attempted to glean the ergogenic benefits of recombinant human erythropoietin (rHuEPO) since it became available in the 1980s. However, there is limited consensus in the literature regarding its true performance-enhancing effects. In fact, some studies suggest there is no conclusive evidence; therefore, it is necessary to evaluate and quantify the strength of the evidence. Objective To determine the effects of erythropoietin on enhancing athletic performance. Design At least two independent reviewers conducted citation identification through abstract and full-text screening, and study selection, and extracted raw data on demographics, descriptions of interventions and all outcomes to predesigned abstraction forms. Outcomes were stratified by treatment periods and dosages. Study quality was assessed using the Cochrane Risk of Bias Tool and Cochrane Grading of Recommendations Assessment Development and Education (GRADE) scale. Where appropriate, quantitative analysis was performed. Data sources EMBASE, MEDLINE and SPORTDiscus were searched from their inception to January 2020. Eligibility criteria Trials that examined any enhancement in sport in healthy participants aged 18-65 using rHuEPO compared with placebo were included. Results Overall, there is low-to-moderate quality evidence suggesting rHuEPO may be more beneficial than placebo in enhancing haematological parameters, pulmonary measures, maximal power output and time to exhaustion independent of dosage. However, these improvements are almost exclusively seen during maximal exercise intensities, which may be less relevant to athletic competition conditions. Conclusion Due to heterogeneity among trials, more high-quality randomised controlled trials with larger sample sizes in conditions that mirror actual competition are needed to further elucidate these effects.
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Affiliation(s)
- Kien Vinh Trinh
- Faculty of Health Sciences, McMaster University, Hamilton, Ontario, Canada
| | - Dion Diep
- MD Program, University of Toronto, Toronto, Ontario, Canada
| | | | - Le Huang
- Department of Bioengineering, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
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HAILE DIRESIBACHEWW, DURUSSEL JÉRÔME, MEKONEN WONDYEFRAW, ONGARO NEFORD, ANJILA EDWIN, MOOSES MARTIN, DASKALAKI EVANGELIA, MOOSES KERLI, MCCLURE JOHND, SUTEHALL SHAUN, PITSILADIS YANNISP. Effects of EPO on Blood Parameters and Running Performance in Kenyan Athletes. Med Sci Sports Exerc 2019; 51:299-307. [DOI: 10.1249/mss.0000000000001777] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Yap KN, Dick MF, Guglielmo CG, Williams TD. Effects of experimental manipulation of hematocrit on avian flight performance in high- and low-altitude conditions. ACTA ACUST UNITED AC 2018; 221:jeb.191056. [PMID: 30266786 DOI: 10.1242/jeb.191056] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2018] [Accepted: 09/21/2018] [Indexed: 12/13/2022]
Abstract
Despite widely held assumptions that hematocrit (Hct) is a key determinant of aerobic capacity and exercise performance, this relationship has not often been tested rigorously in birds and results to date are mixed. Migration in birds involves high-intensity exercise for long durations at various altitudes. Therefore, it provides a good model system to examine the effect of Hct on flight performance and physiological responses of exercise at high altitude. We treated yellow-rumped warblers (Setophaga coronata) with avian erythropoietin (EPO) and anti-EPO to experimentally manipulate Hct and assessed flight performance at low and high altitudes using a hypobaric wind tunnel. We showed that anti-EPO-treated birds had lower Hct than vehicle- and EPO--treated birds post-treatment. Anti-EPO-treated birds also had marginally lower exercise performance at low altitude, committing a higher number of strikes (mistakes) in the first 30 min of flight. However, anti-EPO-treated birds performed significantly better at high altitude, attaining a higher altitude in a ramped altitude challenge to 3000 m equivalent altitude, and with a longer duration of flight at high altitude. Birds exercising at high altitude showed decreased Hct, increased glucose mobilization and decreased antioxidant capacity, regardless of treatment. In summary, we provide experimental evidence that the relationship between Hct and exercise performance is dependent on altitude. Future studies should investigate whether free-living birds adaptively modulate their Hct, potentially through a combination of erythropoiesis and plasma volume regulation (i.e. hemodilution), based on the altitude they fly at during migratory flight.
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Affiliation(s)
- Kang Nian Yap
- Department of Biological Sciences, Simon Fraser University, 8888 University Drive, Burnaby, BC, V5A 1S6, Canada
| | - Morag F Dick
- Department of Biology, Advanced Facility for Avian Research, University of Western Ontario, 1393 Western Road, London, ON, N6G 1G9, Canada
| | - Christopher G Guglielmo
- Department of Biology, Advanced Facility for Avian Research, University of Western Ontario, 1393 Western Road, London, ON, N6G 1G9, Canada
| | - Tony D Williams
- Department of Biological Sciences, Simon Fraser University, 8888 University Drive, Burnaby, BC, V5A 1S6, Canada
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GSK3β: a plausible mechanism of cognitive and hippocampal changes induced by erythropoietin treatment in mood disorders? Transl Psychiatry 2018; 8:216. [PMID: 30310078 PMCID: PMC6181907 DOI: 10.1038/s41398-018-0270-z] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/08/2017] [Revised: 06/11/2018] [Accepted: 07/14/2018] [Indexed: 12/16/2022] Open
Abstract
Mood disorders are associated with significant psychosocial and occupational disability. It is estimated that major depressive disorder (MDD) will become the second leading cause of disability worldwide by 2020. Existing pharmacological and psychological treatments are limited for targeting cognitive dysfunctions in mood disorders. However, growing evidence from human and animal studies has shown that treatment with erythropoietin (EPO) can improve cognitive function. A recent study involving EPO-treated patients with mood disorders showed that the neural basis for their cognitive improvements appeared to involve an increase in hippocampal volume. Molecular mechanisms underlying hippocampal changes have been proposed, including the activation of anti-apoptotic, antioxidant, pro-survival and anti-inflammatory signalling pathways. The aim of this review is to describe the potential importance of glycogen synthase kinase 3-beta (GSK3β) as a multi-potent molecular mechanism of EPO-induced hippocampal volume change in mood disorder patients. We first examine published associations between EPO administration, mood disorders, cognition and hippocampal volume. We then highlight evidence suggesting that GSK3β influences hippocampal volume in MDD patients, and how this could assist with targeting more precise treatments particularly for cognitive deficits in patients with mood disorders. We conclude by suggesting how this developing area of research can be further advanced, such as using pharmacogenetic studies of EPO treatment in patients with mood disorders.
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Aachmann‐Andersen NJ, Christensen SJ, Lisbjerg K, Oturai P, Johansson PI, Holstein‐Rathlou N, Olsen NV. Recombinant erythropoietin acutely decreases renal perfusion and decouples the renin-angiotensin-aldosterone system. Physiol Rep 2018; 6:e13573. [PMID: 29504258 PMCID: PMC5835499 DOI: 10.14814/phy2.13573] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2017] [Revised: 12/07/2017] [Accepted: 12/09/2017] [Indexed: 11/24/2022] Open
Abstract
The effect of recombinant erythropoietin (rhEPO) on renal and systemic hemodynamics was evaluated in a randomized double-blinded, cross-over study. Sixteen healthy subjects were tested with placebo, or low-dose rhEPO for 2 weeks, or high-dose rhEPO for 3 days. Subjects refrained from excessive salt intake, according to instructions from a dietitian. Renal clearance studies were done for measurements of renal plasma flow, glomerular filtration rate (GFR) and the segmentel tubular handling of sodium and water (lithium clearance). rhEPO increased arterial blood pressure, total peripheral resistance, and renal vascular resistance, and decreased renal plasma flow in the high-dose rhEPO intervention and tended to decrease GFR. In spite of the decrease in renal perfusion, rhEPO tended to decrease reabsorption of sodium and water in the proximal tubule and induced a prompt decrease in circulating levels of renin and aldosterone, independent of changes in red blood cell mass, blood volumes, and blood pressure. We also found changes in biomarkers showing evidence that rhEPO induced a prothrombotic state. Our results suggest that rhEPO causes a direct downregulation in proximal tubular reabsorption that seems to decouple the activity of the renin-angiotensin-aldosterone system from changes in renal hemodynamics. This may serve as a negative feed-back mechanism on endogenous synthesis of EPO when circulating levels of EPO are high. These results demonstrates for the first time in humans a direct effect of rhEPO on renal hemodynamics and a decoupling of the renin-angiotensin-aldosterone system.
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Affiliation(s)
| | - Soren J. Christensen
- Department of Neuroscience and PharmacologyUniversity of CopenhagenCopenhagenDenmark
| | - Kristian Lisbjerg
- Department of Neuroscience and PharmacologyUniversity of CopenhagenCopenhagenDenmark
| | - Peter Oturai
- Department of Clinical Physiology, Nuclear Medicine and PETThe Diagnostic Centre, RigshospitaletCopenhagenDenmark
| | - Pär I. Johansson
- Section for Transfusion MedicineCapital Region Blood BankThe Diagnostic Centre, RigshospitaletCopenhagenDenmark
- Department of SurgeryUniversity of Texas Health Medical SchoolHoustonTexas
| | | | - Niels V. Olsen
- Department of Neuroscience and PharmacologyUniversity of CopenhagenCopenhagenDenmark
- Department of NeuroanaesthesiaThe Neuroscience Centre, RigshospitaletCopenhagenDenmark
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Vestergaard MB, Henriksen OM, Lindberg U, Aachmann-Andersen NJ, Lisbjerg K, Christensen SJ, Olsen NV, Law I, Larsson HBW, Rasmussen P. No evidence for direct effects of recombinant human erythropoietin on cerebral blood flow and metabolism in healthy humans. J Appl Physiol (1985) 2018; 124:1107-1116. [PMID: 29357480 DOI: 10.1152/japplphysiol.00869.2017] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Erythropoietin (EPO) is expressed in human brain tissue, but its exact role is unknown. EPO may improve the efficiency of oxidative metabolism and has neuroprotective properties against hypoxic injuries in animal models. We aimed to investigate the effect of recombinant human EPO (rHuEPO) administration on healthy cerebral metabolism in humans during normoxia and during metabolic stress by inhalation of 10% O2 hypoxic air. Twenty-four healthy men participated in a two-arm double-blind placebo-controlled trial. rHuEPO was administered as a low dose (5,000 IU) over 4 wk ( n = 12) or as a high dose (500 IU·kg body wt-1·day-1) for three consecutive days ( n = 12). Global cerebral blood flow (CBF) and metabolic rate of glucose (CMRglc) were measured with positron emission tomography. CBF, metabolic rate of oxygen ([Formula: see text]), and cerebral lactate concentration were measured by magnetic resonance imaging and spectroscopy. Low-dose treatment increased hemoglobin and was associated with a near-significant decrease in CBF during baseline normoxia. High-dose treatment caused no change in CBF. Neither treatment had an effect on normoxia CMRglc, [Formula: see text], or lactate concentration or an effect on the cerebral metabolic response to inhalation of hypoxic air. In conclusion, the study found no evidence for a direct effect of rHuEPO on cerebral metabolism. NEW & NOTEWORTHY We demonstrate with magnetic resonance imaging and positron emission tomography that administration of erythropoietin does not have a substantial direct effect on healthy human resting cerebral blood flow or effect on cerebral glucose and oxygen metabolism. Also, administration of erythropoietin did not have a direct effect on the metabolic response to acute hypoxic stress in healthy humans, and a suggested neuroprotective effect from erythropoietin is therefore likely not a direct effect of erythropoietin on cerebral metabolism.
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Affiliation(s)
- Mark Bitsch Vestergaard
- Functional Imaging Unit, Department of Clinical Physiology, Nuclear Medicine, and PET, Copenhagen University Hospital Rigshospitalet, Glostrup, Denmark
| | - Otto Mølby Henriksen
- Department of Clinical Physiology, Nuclear Medicine, and PET, Copenhagen University Hospital Rigshospitalet , Copenhagen , Denmark
| | - Ulrich Lindberg
- Functional Imaging Unit, Department of Clinical Physiology, Nuclear Medicine, and PET, Copenhagen University Hospital Rigshospitalet, Glostrup, Denmark
| | - Niels Jacob Aachmann-Andersen
- Department of Neuroscience and Pharmacology, Faculty of Health Sciences, University of Copenhagen , Copenhagen , Denmark
| | - Kristian Lisbjerg
- Department of Neuroscience and Pharmacology, Faculty of Health Sciences, University of Copenhagen , Copenhagen , Denmark
| | - Søren Just Christensen
- Department of Neuroscience and Pharmacology, Faculty of Health Sciences, University of Copenhagen , Copenhagen , Denmark
| | - Niels Vidiendal Olsen
- Department of Neuroanaesthesia, The Neuroscience Centre, Copenhagen University Hospital Rigshospitalet Blegdamsvej , Copenhagen , Denmark
| | - Ian Law
- Department of Clinical Physiology, Nuclear Medicine, and PET, Copenhagen University Hospital Rigshospitalet , Copenhagen , Denmark
| | - Henrik Bo Wiberg Larsson
- Functional Imaging Unit, Department of Clinical Physiology, Nuclear Medicine, and PET, Copenhagen University Hospital Rigshospitalet, Glostrup, Denmark
| | - Peter Rasmussen
- Department of Neuroscience and Pharmacology, Faculty of Health Sciences, University of Copenhagen , Copenhagen , Denmark
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Heuberger JAAC, Rotmans JI, Gal P, Stuurman FE, van 't Westende J, Post TE, Daniels JMA, Moerland M, van Veldhoven PLJ, de Kam ML, Ram H, de Hon O, Posthuma JJ, Burggraaf J, Cohen AF. Effects of erythropoietin on cycling performance of well trained cyclists: a double-blind, randomised, placebo-controlled trial. LANCET HAEMATOLOGY 2017; 4:e374-e386. [PMID: 28669689 DOI: 10.1016/s2352-3026(17)30105-9] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/14/2017] [Revised: 05/26/2017] [Accepted: 05/26/2017] [Indexed: 12/22/2022]
Abstract
BACKGROUND Substances that potentially enhance performance (eg, recombinant human erythropoietin [rHuEPO]) are considered doping and are therefore forbidden in sports; however, the scientific evidence behind doping is frequently weak. We aimed to determine the effects of rHuEPO treatment in well trained cyclists on maximal, submaximal, and race performance and on safety, and to present a model clinical study for doping research on other substances. METHODS We did this double-blind, randomised, placebo-controlled trial at the Centre for Human Drug Research in Leiden (Netherlands). We enrolled healthy, well trained but non-professional male cyclists aged 18-50 years and randomly allocated (1:1) them to receive abdominal subcutaneous injections of rHuEPO (epoetin β; mean dose 6000 IU per week) or placebo (0·9% NaCl) for 8 weeks. Randomisation was stratified by age groups (18-34 years and 35-50 years), with a code generated by a statistician who was not masked to the study. The primary outcome was exercise performance, measured as maximal power output (Pmax), maximal oxygen consumption VO2 max, and gross efficiency in maximal exercise tests with 25 W increments per 5 min, as lactate threshold and ventilatory threshold 1 (VT1) and 2 (VT2) at submaximal levels during the maximal exercise test, and as mean power, VO2, and heart rate in the submaximal exercise tests at the highest mean power output for 45 min in a laboratory setting and in a race to the Mont Ventoux (France) summit, using intention-to-treat analyses. The trial is registered with the Dutch Trial Registry (Nederlands Trial Register), number NTR5643. FINDINGS Between March 7, 2016, and April 13, 2016, we randomly assigned 48 participants to the rHuEPO group (n=24) or the placebo group (n=24). Mean haemoglobin concentration (9·6 mmol/L vs 9·0 mmol/L [estimated difference 0·6, 95% CI 0·4 to 0·8]) and maximal power output (351·55 W vs 341·23 W [10·32, 3·47 to 17·17]), and VO2 max (60·121 mL/min per kg vs 57·415 mL/min per kg [2·707, 0·911 to 4·503]) in a maximal exercise test were higher in the rHuEPO group compared with the placebo group. Submaximal exercise test parameters mean power output (283·18 W vs 277·28 W [5·90, -0·87 to 12·67]) and VO2 (50·288 mL/min per kg vs 49·642 mL/min per kg [0·646, -1·307 to 2·600]) at day 46, and Mont Ventoux race times (1 h 40 min 32 s vs 1 h 40 min 15 s [0·3%, -8·3 to 9·6]) did not differ between groups. All adverse events were grade 1-2 and were similar between both groups. No events of grade 3 or worse were observed. INTERPRETATION Although rHuEPO treatment improved a laboratory test of maximal exercise, the more clinically relevant submaximal exercise test performance and road race performance were not affected. This study shows that clinical studies with doping substances can be done adequately and safely and are relevant in determining effects of alleged performance-enhancing drugs. FUNDING Centre for Human Drug Research, Leiden.
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Affiliation(s)
| | - Joris I Rotmans
- Department of Internal Medicine, Leiden University Medical Centre, Leiden, Netherlands
| | - Pim Gal
- Centre for Human Drug Research, Leiden, Netherlands
| | | | - Juliëtte van 't Westende
- Centre for Human Drug Research, Leiden, Netherlands; Leiden Academic Centre for Drug Research, Leiden, Netherlands
| | - Titiaan E Post
- Centre for Human Drug Research, Leiden, Netherlands; Leiden Academic Centre for Drug Research, Leiden, Netherlands
| | - Johannes M A Daniels
- Department of Pulmonary Diseases, VU University Medical Centre, Amsterdam, Netherlands
| | | | | | | | - Herman Ram
- Anti-Doping Authority of the Netherlands, Capelle aan de IJssel, Netherlands
| | - Olivier de Hon
- Anti-Doping Authority of the Netherlands, Capelle aan de IJssel, Netherlands
| | - Jelle J Posthuma
- Cardiovascular Research Institute Maastricht, Maastricht University, Maastricht, Netherlands
| | - Jacobus Burggraaf
- Centre for Human Drug Research, Leiden, Netherlands; Leiden Academic Centre for Drug Research, Leiden, Netherlands
| | - Adam F Cohen
- Centre for Human Drug Research, Leiden, Netherlands; Department of Internal Medicine, Leiden University Medical Centre, Leiden, Netherlands
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12
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Carbamylated erythropoietin enhances mice ventilatory responses to changes in O2 but not CO2 levels. Respir Physiol Neurobiol 2016; 232:1-12. [PMID: 27317882 DOI: 10.1016/j.resp.2016.06.002] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2016] [Revised: 06/14/2016] [Accepted: 06/15/2016] [Indexed: 11/21/2022]
Abstract
Erythropoietin (EPO) has beneficial tissue-protective effects in several diseases but erythrocytosis may cause deleterious effects in EPO-treated patients. Thus carbamylated-EPO (C-EPO) and other derivatives retaining tissue-protective but lacking bone marrow-stimulating actions have been developed. Although EPO modulates ventilatory responses, the effects of C-EPO on ventilation have not been investigated. Here, basal breathing and respiratory chemoreflexes were measured by plethysmography after acute and chronic treatments with recombinant human C-EPO (rhC-EPO; 15,000 IU/kg during 5days) or saline (control group). Hematocrit, plasma and brainstem rhC-EPO levels were also quantified. Chronic rhC-EPO significantly elevated tissue rhC-EPO levels but not hematocrit. None of the drug regimen altered basal ventilation (normoxia). Chronic but not acute rhC-EPO enhanced hyperoxic ventilatory depression, and sustained the hypoxic ventilatory response mainly via a reduction of the roll-off phase. By contrast, rhC-EPO did not blunt the ventilatory response to hypercapnia. Thus, chronic C-EPO may be a promising therapy to improve breathing during hypoxia while minimizing adverse effects on cardiovascular function.
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13
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Bejder J, Aachmann-Andersen NJ, Bonne TC, Olsen NV, Nordsborg NB. Detection of erythropoietin misuse by the Athlete Biological Passport combined with reticulocyte percentage. Drug Test Anal 2015; 8:1049-1055. [DOI: 10.1002/dta.1932] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2015] [Revised: 11/12/2015] [Accepted: 11/16/2015] [Indexed: 12/12/2022]
Affiliation(s)
- Jacob Bejder
- Department of Nutrition, Exercise and Sport Sciences; University of Copenhagen; Copenhagen Denmark
| | | | - Thomas Christian Bonne
- Department of Nutrition, Exercise and Sport Sciences; University of Copenhagen; Copenhagen Denmark
| | - Niels Vidiendal Olsen
- Department of Neuroscience and Pharmacology; University of Copenhagen
- Department of Neuroanesthesia, The Neuroscience Center; Copenhagen University Hospital (Rigshospitalet); Copenhagen Denmark
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14
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Bishop-Bailey D. Mechanisms governing the health and performance benefits of exercise. Br J Pharmacol 2014; 170:1153-66. [PMID: 24033098 DOI: 10.1111/bph.12399] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2013] [Revised: 07/18/2013] [Accepted: 07/23/2013] [Indexed: 12/18/2022] Open
Abstract
Humans are considered among the greatest if not the greatest endurance land animals. Over the last 50 years, as the population has become more sedentary, rates of cardiovascular disease and its associated risk factors such as obesity, type 2 diabetes and hypertension have all increased. Aerobic fitness is considered protective for all-cause mortality, cardiovascular disease, a variety of cancers, joint disease and depression. Here, I will review the emerging mechanisms that underlie the response to exercise, focusing on the major target organ the skeletal muscle system. Understanding the mechanisms of action of exercise will allow us to develop new therapies that mimic the protective actions of exercise.
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Affiliation(s)
- D Bishop-Bailey
- Comparative Biomedical Sciences, The Royal Veterinary College, London, UK
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15
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Aachmann-Andersen NJ, Just Christensen S, Lisbjerg K, Oturai P, Meinild-Lundby AK, Holstein-Rathlou NH, Lundby C, Vidiendal Olsen N. Recombinant erythropoietin in humans has a prolonged effect on circulating erythropoietin isoform distribution. PLoS One 2014; 9:e110903. [PMID: 25335123 PMCID: PMC4204994 DOI: 10.1371/journal.pone.0110903] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2014] [Accepted: 09/24/2014] [Indexed: 11/18/2022] Open
Abstract
The membrane-assisted isoform immunoassay (MAIIA) quantitates erythropoietin (EPO) isoforms as percentages of migrated isoforms (PMI). We evaluated the effect of recombinant human EPO (rhEPO) on the distribution of EPO isoforms in plasma in a randomized, placebo-controlled, double-blinded, cross-over study. 16 healthy subjects received either low-dose Epoetin beta (5000 IU on days 1, 3, 5, 7, 9, 11 and 13); high-dose Epoetin beta (30.000 IU on days 1, 2 and 3 and placebo on days 5, 7, 9, 11 and 13); or placebo on all days. PMI on days 4, 11 and 25 was determined by interaction of N-acetyl glucosamine with the glycosylation dependent desorption of EPO isoforms. At day 25, plasma-EPO in both rhEPO groups had returned to values not different from the placebo group. PMI with placebo, reflecting the endogenous EPO isoforms, averaged 82.5 (10.3) % (mean (SD)). High-dose Epoetin beta decreased PMI on days 4 and 11 to 31.0 (4.2)% (p<0.00001) and 45.2 (7.3)% (p<0.00001). Low-dose Epoetin beta decreased PMI on days 4 and 11 to 46.0 (12.8)% (p<0.00001) and 46.1 (10.4)% (p<0.00001). In both rhEPO groups, PMI on day 25 was still decreased (high-dose Epoetin beta: 72.9 (19.4)% (p = 0.029); low-dose Epoetin beta: 73.1 (17.8)% (p = 0.039)). In conclusion, Epoetin beta leaves a footprint in the plasma-EPO isoform pattern. MAIIA can detect changes in EPO isoform distribution up til at least three weeks after administration of Epoetin beta even though the total EPO concentration has returned to normal.
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Affiliation(s)
| | - Søren Just Christensen
- Department of Neuroscience and Pharmacology, University of Copenhagen, Copenhagen, Denmark
| | - Kristian Lisbjerg
- Department of Neuroscience and Pharmacology, University of Copenhagen, Copenhagen, Denmark
| | - Peter Oturai
- Clinic of Clinical Physiology, Nuclear Medicine and PET, Centre of Clinical Investigation, Rigshospitalet, Copenhagen, Denmark
| | - Anne-Kristine Meinild-Lundby
- Center for Integrative Human Physiology (ZIHP), University of Zurich, Institute of Physiology, Zürich, Switzerland
| | | | - Carsten Lundby
- Center for Integrative Human Physiology (ZIHP), University of Zurich, Institute of Physiology, Zürich, Switzerland
| | - Niels Vidiendal Olsen
- Department of Neuroscience and Pharmacology, University of Copenhagen, Copenhagen, Denmark
- Department of Neuroanaesthesia, The Neuroscience Centre, Rigshospitalet, Copenhagen, Denmark
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16
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Lamon S, Zacharewicz E, Stephens AN, Russell AP. EPO-receptor is present in mouse C2C12 and human primary skeletal muscle cells but EPO does not influence myogenesis. Physiol Rep 2014; 2:e00256. [PMID: 24760510 PMCID: PMC4002236 DOI: 10.1002/phy2.256] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
The role and regulation of the pleiotropic cytokine erythropoietin (EPO) in skeletal muscle are controversial. EPO exerts its effects by binding its specific receptor (EPO‐R), which activates intracellular signaling and gene transcription in response to internal and external stress signals. EPO is suggested to play a direct role in myogenesis via the EPO‐R, but several studies have questioned the effect of EPO treatment in muscle in vitro and in vivo. The lack of certainty surrounding the use of nonspecific EPO‐R antibodies contributes to the ambiguity of the field. Our study demonstrates that the EPO‐R gene and protein are expressed at each stage of mouse C2C12 and human skeletal muscle cell proliferation and differentiation and validates a specific antibody for the detection of the EPO‐R protein. However, in our experimental conditions, EPO treatment had no effect on mouse C2C12 and human muscle cell proliferation, differentiation, protein synthesis or EPO‐R expression. While an increase in Akt and MAPK phosphorylation was observed, we demonstrate that this effect resulted from the stress caused by changing medium and not from EPO treatment. We therefore suggest that skeletal muscle EPO‐R might be present in a nonfunctional form, or too lowly expressed to play a role in muscle cell function. The EPO‐R is expressed at the gene and protein level in mouse and human myoblasts and myotubes. However, EPO treatment does not seem to activate the EPO‐R and its downstream signaling pathways in skeletal muscle cells, questioning its functionality.
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Affiliation(s)
- Séverine Lamon
- Centre for Physical Activity and Nutrition, School of Exercise and Nutrition Sciences, Deakin University, Burwood, Victoria, Australia
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17
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Chapman RF, Karlsen T, Resaland GK, Ge RL, Harber MP, Witkowski S, Stray-Gundersen J, Levine BD. Defining the “dose” of altitude training: how high to live for optimal sea level performance enhancement. J Appl Physiol (1985) 2014; 116:595-603. [DOI: 10.1152/japplphysiol.00634.2013] [Citation(s) in RCA: 74] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Chronic living at altitudes of ∼2,500 m causes consistent hematological acclimatization in most, but not all, groups of athletes; however, responses of erythropoietin (EPO) and red cell mass to a given altitude show substantial individual variability. We hypothesized that athletes living at higher altitudes would experience greater improvements in sea level performance, secondary to greater hematological acclimatization, compared with athletes living at lower altitudes. After 4 wk of group sea level training and testing, 48 collegiate distance runners (32 men, 16 women) were randomly assigned to one of four living altitudes (1,780, 2,085, 2,454, or 2,800 m). All athletes trained together daily at a common altitude from 1,250–3,000 m following a modified live high-train low model. Subjects completed hematological, metabolic, and performance measures at sea level, before and after altitude training; EPO was assessed at various time points while at altitude. On return from altitude, 3,000-m time trial performance was significantly improved in groups living at the middle two altitudes (2,085 and 2,454 m), but not in groups living at 1,780 and 2,800 m. EPO was significantly higher in all groups at 24 and 48 h, but returned to sea level baseline after 72 h in the 1,780-m group. Erythrocyte volume was significantly higher within all groups after return from altitude and was not different between groups. These data suggest that, when completing a 4-wk altitude camp following the live high-train low model, there is a target altitude between 2,000 and 2,500 m that produces an optimal acclimatization response for sea level performance.
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Affiliation(s)
| | - Trine Karlsen
- Norwegian University of Sport and Physical Education, Oslo, Norway
| | - Geir K. Resaland
- Norwegian University of Sport and Physical Education, Oslo, Norway
| | - R.-L. Ge
- Research Center for High Altitude Medicine, Qinghai University, Xining, Qinghai, China; and
| | - Matthew P. Harber
- Institute for Exercise and Environmental Medicine, Presbyterian Hospital of Dallas, The University of Texas Southwestern Medical Center, Dallas, Texas
| | - Sarah Witkowski
- Institute for Exercise and Environmental Medicine, Presbyterian Hospital of Dallas, The University of Texas Southwestern Medical Center, Dallas, Texas
| | | | - Benjamin D. Levine
- Institute for Exercise and Environmental Medicine, Presbyterian Hospital of Dallas, The University of Texas Southwestern Medical Center, Dallas, Texas
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18
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Heuberger JAAC, Cohen Tervaert JM, Schepers FML, Vliegenthart ADB, Rotmans JI, Daniels JMA, Burggraaf J, Cohen AF. Erythropoietin doping in cycling: lack of evidence for efficacy and a negative risk-benefit. Br J Clin Pharmacol 2014; 75:1406-21. [PMID: 23216370 DOI: 10.1111/bcp.12034] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2012] [Accepted: 11/09/2012] [Indexed: 11/29/2022] Open
Abstract
Imagine a medicine that is expected to have very limited effects based upon knowledge of its pharmacology and (patho)physiology and that is studied in the wrong population, with low-quality studies that use a surrogate end-point that relates to the clinical end-point in a partial manner at most. Such a medicine would surely not be recommended. The use of recombinant human erythropoietin (rHuEPO) to enhance performance in cycling is very common. A qualitative systematic review of the available literature was performed to examine the evidence for the ergogenic properties of this drug, which is normally used to treat anaemia in chronic renal failure patients. The results of this literature search show that there is no scientific basis from which to conclude that rHuEPO has performance-enhancing properties in elite cyclists. The reported studies have many shortcomings regarding translation of the results to professional cycling endurance performance. Additionally, the possibly harmful side-effects have not been adequately researched for this population but appear to be worrying, at least. The use of rHuEPO in cycling is rife but scientifically unsupported by evidence, and its use in sports is medical malpractice. What its use would have been, if the involved team physicians had been trained in clinical pharmacology and had investigated this properly, remains a matter of speculation. A single well-controlled trial in athletes in real-life circumstances would give a better indication of the real advantages and risk factors of rHuEPO use, but it would be an oversimplification to suggest that this would eradicate its use.
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19
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Scharhag-Rosenberger F, Carlsohn A, Lundby C, Schüler S, Mayer F, Scharhag J. Can more than one incremental cycling test be performed within one day? Eur J Sport Sci 2013; 14:459-67. [DOI: 10.1080/17461391.2013.853208] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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20
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Haemoglobin mass and running time trial performance after recombinant human erythropoietin administration in trained men. PLoS One 2013; 8:e56151. [PMID: 23418527 PMCID: PMC3571963 DOI: 10.1371/journal.pone.0056151] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2012] [Accepted: 01/05/2013] [Indexed: 11/19/2022] Open
Abstract
Recombinant human erythropoietin (rHuEpo) increases haemoglobin mass (Hbmass) and maximal oxygen uptake ( O2 max).
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21
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Jacobs RA, Lundby C, Robach P, Gassmann M. Red blood cell volume and the capacity for exercise at moderate to high altitude. Sports Med 2012; 42:643-63. [PMID: 22741918 DOI: 10.1007/bf03262286] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Hypoxia-stimulated erythropoiesis, such as that observed when red blood cell volume (RCV) increases in response to high-altitude exposure, is well understood while the physiological importance is not. Maximal exercise tests are often performed in hypoxic conditions following some form of RCV manipulation in an attempt to elucidate oxygen transport limitations at moderate to high altitudes. Such attempts, however, have not made clear the extent to which RCV is of benefit to exercise at such elevations. Changes in RCV at sea level clearly have a direct influence on maximal exercise capacity. Nonetheless, at elevations above 3000 m, the evidence is not that clear. Certain studies demonstrate either a direct benefit or decrement to exercise capacity in response to an increase or decrease, respectively, in RCV whereas other studies report negligible effects of RCV manipulation on exercise capacity. Adding to the uncertainty regarding the importance of RCV at high altitude is the observation that Andean and Tibetan high-altitude natives exhibit similar exercise capacities at high altitude (3900 m) even though Andean natives often present with a higher percent haematocrit (Hct) when compared with both lowland natives and Tibetans. The current review summarizes past literature that has examined the effect of RCV changes on maximal exercise capacity at moderate to high altitudes, and discusses the explanation elucidating these seemingly paradoxical observations.
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Affiliation(s)
- Robert A Jacobs
- Institute of Veterinary Physiology, Vetsuisse Faculty, University of Zurich, Zurich, Switzerland
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22
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Schuler B, Vogel J, Grenacher B, Jacobs RA, Arras M, Gassmann M. Acute and chronic elevation of erythropoietin in the brain improves exercise performance in mice without inducing erythropoiesis. FASEB J 2012; 26:3884-90. [PMID: 22683849 DOI: 10.1096/fj.11-191197] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Application of recombinant human erythropoietin (rhEpo) improves exercise capacity by stimulating red blood cell production that, in turn, enhances oxygen delivery and utilization. Apart from this, when applied at high doses, rhEpo crosses the blood-brain barrier, triggering protective neuronal effects. Here we show a fundamental new role by which the presence of Epo in the brain augments exercise performance without altering red blood cell production. Two different animal models, the transgenic mouse line Tg21, which constitutively overexpresses human Epo exclusively in the brain without affecting erythropoiesis, and wild-type mice treated with a single high dose of rhEpo, demonstrate an unexpected improvement in maximal exercise performance independent of changes in total hemoglobin mass, as well as in whole blood volume and cardiovascular parameters. This novel finding builds a more complete understanding regarding the central effects of endogenously produced and exogenously applied Epo on exercise performance.
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Affiliation(s)
- Beat Schuler
- Institute of Veterinary Physiology, Vetsuisse Faculty, and Zurich Center for Integrative Human Physiology, University of Zurich, Zurich, Switzerland
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23
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Jacobs RA, Lundby C, Robach P, Gassmann M. Red Blood Cell Volume and the Capacity for Exercise at Moderate to High Altitude. Sports Med 2012. [DOI: 10.2165/11632440-000000000-00000] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
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24
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Lundby C, Robach P, Saltin B. The evolving science of detection of 'blood doping'. Br J Pharmacol 2012; 165:1306-15. [PMID: 22225538 PMCID: PMC3372716 DOI: 10.1111/j.1476-5381.2011.01822.x] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2011] [Revised: 11/15/2011] [Accepted: 11/25/2011] [Indexed: 12/21/2022] Open
Abstract
Blood doping practices in sports have been around for at least half a century and will likely remain for several years to come. The main reason for the various forms of blood doping to be common is that they are easy to perform, and the effects on exercise performance are gigantic. Yet another reason for blood doping to be a popular illicit practice is that detection is difficult. For autologous blood transfusions, for example, no direct test exists, and the direct testing of misuse with recombinant human erythropoietin (rhEpo) has proven very difficult despite a test exists. Future blood doping practice will likely include the stabilization of the transcription factor hypoxia-inducible factor which leads to an increased endogenous erythropoietin synthesis. It seems unrealistic to develop specific test against such drugs (and the copies hereof originating from illegal laboratories). In an attempt to detect and limit blood doping, the World Anti-Doping Agency (WADA) has launched the Athlete Biological Passport where indirect markers for all types of blood doping are evaluated on an individual level. The approach seemed promising, but a recent publication demonstrates the system to be incapable of detecting even a single subject as 'suspicious' while treated with rhEpo for 10-12 weeks. Sad to say, the hope that the 2012 London Olympics should be cleaner in regard to blood doping seems faint. We propose that WADA strengthens the quality and capacities of the National Anti-Doping Agencies and that they work more efficiently with the international sports federations in an attempt to limit blood doping.
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Affiliation(s)
- Carsten Lundby
- Center for Integrative Human Physiology, Institute of Physiology, University of Zurich, Switzerland.
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25
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Abstract
Traditionally, erythropoietin (EPO) is described as a hematopoietic cytokine, regulating proliferation and differentiation and survival of the erythroid progenitors. The recent finding of new sites of EPO production and the wide spread distribution of EPO receptors (EPO-R) on endothelial cells, cardiomyocytes, renal cells as well as the central and peripheral nervous system raised the possibility that EPO may exert pleiotropic actions on several targets. Indeed studies (mainly preclinical) have documented protective, non-hematopoietic, abilities of EPO in a variety of tissue. However, the data obtained from clinical studies are more skeptical about these properties. This article provides a comprehensive overview of EPO and its derivatives.
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Affiliation(s)
- Mariusz Kowalczyk
- Department of Nephrology, Hypertension and Family Medicine, Chair of Nephrology and Hypertension, Medical University of Lodz, Poland
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26
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Rasmussen P, Nordsborg N, Taudorf S, S⊘rensen H, Berg RMG, Jacobs RA, Bailey DM, Olsen NV, Secher NH, M⊘ller K, Lundby C. Brain and skin do not contribute to the systemic rise in erythropoietin during acute hypoxia in humans. FASEB J 2012; 26:1831-4. [DOI: 10.1096/fj.11-191692] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Peter Rasmussen
- Zurich Centre for Integrative Human PhysiologyDepartment of PhysiologyUniversität ZurichZurichSwitzerland
- Copenhagen Muscle Research CentreRigshospitaletCopenhagenDenmark
- Department of Neuroscience and PharmacologyUniversity of CopenhagenDenmark
| | - Nikolai Nordsborg
- Department of Sports and Exercise ScienceUniversity of CopenhagenDenmark
| | - Sarah Taudorf
- Centre of Inflammation and MetabolismRigshospitaletCopenhagenDenmark
| | | | - Ronan M. G. Berg
- Centre of Inflammation and MetabolismRigshospitaletCopenhagenDenmark
| | - Robert A. Jacobs
- Zurich Centre for Integrative Human PhysiologyDepartment of PhysiologyUniversität ZurichZurichSwitzerland
| | - Damian M. Bailey
- Neurovascular Research LaboratoryFaculty of Health, Science, and SportUniversity of GlamorganCardiffUK
| | - Niels V. Olsen
- Department of AnesthesiologyRigshospitaletCopenhagenDenmark
- Department of Neuroscience and PharmacologyUniversity of CopenhagenDenmark
| | - Niels H. Secher
- Copenhagen Muscle Research CentreRigshospitaletCopenhagenDenmark
- Department of AnesthesiologyRigshospitaletCopenhagenDenmark
| | - Kirsten M⊘ller
- Centre of Inflammation and MetabolismRigshospitaletCopenhagenDenmark
- Department of AnesthesiologyRigshospitaletCopenhagenDenmark
- Department of AnesthesiologyBispebjerg HospitalCopenhagenDenmark
- Department of Neuroscience and PharmacologyUniversity of CopenhagenDenmark
| | - Carsten Lundby
- Zurich Centre for Integrative Human PhysiologyDepartment of PhysiologyUniversität ZurichZurichSwitzerland
- Copenhagen Muscle Research CentreRigshospitaletCopenhagenDenmark
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27
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Christensen B, Vendelbo MH, Krusenstjerna-Hafstrøm T, Madsen M, Pedersen SB, Jessen N, Møller N, Jørgensen JOL. Erythropoietin administration acutely stimulates resting energy expenditure in healthy young men. J Appl Physiol (1985) 2012; 112:1114-21. [PMID: 22241056 DOI: 10.1152/japplphysiol.01391.2011] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Treatment with recombinant human erythropoietin (rHuEpo) improves insulin sensitivity in patients with end-stage renal disease, and animal studies indicate that Epo increases fat oxidation. However, the metabolic effects of rHuEpo have never been experimentally studied in healthy humans. The aim was to investigate the effects of an acute rHuEpo bolus on substrate metabolism and insulin sensitivity in healthy young men. Ten healthy young men were studied in a single-blinded, randomized crossover design with a 2-wk washout period receiving 400 IU/kg rHuEpo or placebo. Substrate metabolism was evaluated by indirect calorimetry and tracer infusions, and insulin sensitivity by a hyperinsulinemic euglycemic clamp; and PCR and Western blotting measured protein expression and content, respectively. Resting energy expenditure (REE) increased significantly after rHuEpo [basal: 1,863.3 ± 67.2 (kcal/day) (placebo) vs. 2,041.6 ± 81.2 (rHuEpo), P < 0.001; clamp: 1,903.9 ± 68.3 (placebo) vs. 2,015.7 ± 114.4 (rHuEpo), P = 0.03], but the increase could not be explained by changes in mRNA levels of uncoupling protein 2 or 3. Fat oxidation in the basal state tended to be higher after rHuEpo but could not be explained by changes in mRNA levels of CPT1 and PPARα or AMPK and ACC protein phosphorylation. Insulin-stimulated glucose disposal, glucose metabolism, and whole body and forearm protein metabolism did not change significantly in response to rHuEpo. In conclusion, a single injection of rHuEpo acutely increases REE in healthy human subjects. This calorigenic effect is not accompanied by distinct alterations in the pattern of substrate metabolism or insulin sensitivity.
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Affiliation(s)
- Britt Christensen
- Department of Medicine and Endocrinology, Aarhus University Hospital, Aarhus, Denmark.
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28
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Hydrogel delivery of erythropoietin to the brain for endogenous stem cell stimulation after stroke injury. Biomaterials 2012; 33:2681-92. [PMID: 22217804 DOI: 10.1016/j.biomaterials.2011.12.031] [Citation(s) in RCA: 91] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2011] [Accepted: 12/17/2011] [Indexed: 11/21/2022]
Abstract
Drug delivery to the brain is challenging because systemic delivery requires high doses to achieve diffusion across the blood-brain barrier and often results in systemic toxicity. Intracerebroventricular implantation of a minipump/catheter system provides local delivery, yet results in brain tissue damage and can be prone to infection. An alternate local delivery strategy, epi-cortical delivery, releases the biomolecule directly to the brain while causing minimal tissue disruption. We pursued this strategy with a hyaluronan/methyl cellulose (HAMC) hydrogel for the local release of erythropoietin to induce endogenous neural stem and progenitor cells of the subventricular zone to promote repair after stroke injury in the mouse brain. Erythropoeitin promotes neurogenesis when delivered intraventricularly, thereby making it an ideal biomolecule with which to test this new epi-cortical delivery strategy. We investigated HAMC in terms of the host tissue response and the diffusion of erythropoeitin therefrom in the stroke-injured brain for neural repair. Erythropoietin delivered from HAMC at 4 and 11 days post-stroke resulted in attenuated inflammatory response, reduced stroke cavity size, increased number of both neurons in the peri-infarct region and migratory neuroblasts in the subventricular zone, and decreased apoptosis in both the subventricular zone and the injured cortex. We demonstrate that HAMC-mediated epi-cortical administration is promising for minimally invasive delivery of erythropoeitin to the brain.
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29
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Rasmussen P, Kim Y, Krogh‐Madsen R, Lundby C, Olsen NV, Secher NH, Lieshout JJ. Both acute and prolonged administration of EPO reduce cerebral and systemic vascular conductance in humans. FASEB J 2011; 26:1343-8. [DOI: 10.1096/fj.11-193508] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Peter Rasmussen
- Copenhagen Muscle Research CenterUniversity of CopenhagenCopenhagenDenmark
- Department of AnesthesiaUniversity of CopenhagenCopenhagenDenmark
- Zurich Center for Integrative Human PhysiologyUniversity of ZurichZurichSwitzerland
| | - Yu‐Sok Kim
- Department of Internal MedicineAMC Center for Heart Failure Research, Academic Medical CenterUniversity of AmsterdamAmsterdamThe Netherlands
- Laboratory for Cardiovascular PhysiologyAMC Center for Heart Failure Research, Academic Medical CenterUniversity of AmsterdamAmsterdamThe Netherlands
| | - Rikke Krogh‐Madsen
- Copenhagen Muscle Research CenterUniversity of CopenhagenCopenhagenDenmark
- Department of Infectious DiseasesCenter of Inflammation and Metabolism, RigshospitaletUniversity of CopenhagenCopenhagenDenmark
| | - Carsten Lundby
- Copenhagen Muscle Research CenterUniversity of CopenhagenCopenhagenDenmark
- Zurich Center for Integrative Human PhysiologyUniversity of ZurichZurichSwitzerland
| | - Niels V. Olsen
- Department of AnesthesiaUniversity of CopenhagenCopenhagenDenmark
- Department of Neuroscience and PharmacologyUniversity of CopenhagenCopenhagenDenmark
| | - Niels H. Secher
- Copenhagen Muscle Research CenterUniversity of CopenhagenCopenhagenDenmark
- Department of AnesthesiaUniversity of CopenhagenCopenhagenDenmark
| | - Johannes J. Lieshout
- Department of Internal MedicineAMC Center for Heart Failure Research, Academic Medical CenterUniversity of AmsterdamAmsterdamThe Netherlands
- Laboratory for Cardiovascular PhysiologyAMC Center for Heart Failure Research, Academic Medical CenterUniversity of AmsterdamAmsterdamThe Netherlands
- School of Biomedical SciencesUniversity of Nottingham Medical SchoolQueen's Medical CentreNottinghamUK
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Seifert T, Secher NH. Sympathetic influence on cerebral blood flow and metabolism during exercise in humans. Prog Neurobiol 2011; 95:406-26. [PMID: 21963551 DOI: 10.1016/j.pneurobio.2011.09.008] [Citation(s) in RCA: 75] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2011] [Revised: 09/13/2011] [Accepted: 09/19/2011] [Indexed: 11/26/2022]
Abstract
This review focuses on the possibility that autonomic activity influences cerebral blood flow (CBF) and metabolism during exercise in humans. Apart from cerebral autoregulation, the arterial carbon dioxide tension, and neuronal activation, it may be that the autonomic nervous system influences CBF as evidenced by pharmacological manipulation of adrenergic and cholinergic receptors. Cholinergic blockade by glycopyrrolate blocks the exercise-induced increase in the transcranial Doppler determined mean flow velocity (MCA Vmean). Conversely, alpha-adrenergic activation increases that expression of cerebral perfusion and reduces the near-infrared determined cerebral oxygenation at rest, but not during exercise associated with an increased cerebral metabolic rate for oxygen (CMRO(2)), suggesting competition between CMRO(2) and sympathetic control of CBF. CMRO(2) does not change during even intense handgrip, but increases during cycling exercise. The increase in CMRO(2) is unaffected by beta-adrenergic blockade even though CBF is reduced suggesting that cerebral oxygenation becomes critical and a limited cerebral mitochondrial oxygen tension may induce fatigue. Also, sympathetic activity may drive cerebral non-oxidative carbohydrate uptake during exercise. Adrenaline appears to accelerate cerebral glycolysis through a beta2-adrenergic receptor mechanism since noradrenaline is without such an effect. In addition, the exercise-induced cerebral non-oxidative carbohydrate uptake is blocked by combined beta 1/2-adrenergic blockade, but not by beta1-adrenergic blockade. Furthermore, endurance training appears to lower the cerebral non-oxidative carbohydrate uptake and preserve cerebral oxygenation during submaximal exercise. This is possibly related to an attenuated catecholamine response. Finally, exercise promotes brain health as evidenced by increased release of brain-derived neurotrophic factor (BDNF) from the brain.
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Affiliation(s)
- Thomas Seifert
- Department of Anaesthesia and The Copenhagen Muscle Research Centre, Rigshospitalet 2041, University of Copenhagen, Blegdamsvej 9, DK-2100 Copenhagen Ø, Denmark.
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Abstract
AbstractHemoglobin mass is a key factor for maximal exercise capacity. Some athletes apply prohibited techniques and substances with intent to increase hemoglobin mass and physical performance, and this is often difficult to prove directly. Autologous red blood cell transfusion cannot be traced on reinfusion, and also recombinant erythropoietic proteins are detectable only within a certain timeframe. Novel erythropoietic substances, such as mimetics of erythropoietin (Epo) and activators of the Epo gene, may soon enter the sports scene. In addition, Epo gene transfer maneuvers are imaginable. Effective since December 2009, the World Anti-Doping Agency has therefore implemented “Athlete Biologic Passport Operating Guidelines,” which are based on the monitoring of several parameters for mature red blood cells and reticulocytes. Blood doping may be assumed, when these parameters change in a nonphysiologic way. Hematologists should be familiar with blood doping practices as they may play an important role in evaluating blood profiles of athletes with respect to manipulations, as contrasted with the established diagnosis of clinical disorders and genetic variations.
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Genc S, Zadeoglulari Z, Oner MG, Genc K, Digicaylioglu M. Intranasal erythropoietin therapy in nervous system disorders. Expert Opin Drug Deliv 2010; 8:19-32. [DOI: 10.1517/17425247.2011.540236] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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Abstract
This review describes some of the physiological effects of recombinant human erythropoietin (EPO) in healthy humans. At the blood level EPO increases the arterial O(2) content not only by increasing red blood cell volume, but also by an equally important decrease in plasma volume. Well before that, EPO causes a prompt decrease in plasma levels of renin and aldosterone. Renal clearance studies suggest that EPO decreases renal proximal tubular reabsorption rate leading to activation of the tubuloglomerular feedback mechanism and a fall in glomerular filtration rate. Thus, treatment with EPO may result in suppression of endogenous EPO production through a decrease in intrarenal oxygen consumption. EPO elevates the arterial blood pressure even in healthy subjects. The receptor for EPO is present in many tissues. However, the functional effects of EPO in the skeletal muscle seem limited, and although it has been speculated that non-erythropoietic effects of EPO (angiogenesis, shift in muscle fibre types, cognitive effects) may be responsible for the increase in exercise performance, this has not been confirmed. EPO-induced haemodynamic effects call for careful monitoring during the administration period. The metabolic, hormonal and renal effects of EPO do not seem to range beyond physiologically acceptable limits and are reversible. Taken together, EPO seems safe to use for experimental purposes in healthy volunteers.
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Affiliation(s)
- Carsten Lundby
- Center for Integrative Human Physiology, University of Zurich, Institute of Physiology, Room 23 H 6, Winterthurerstr. 190, 8057 Zürich, Switzerland.
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Olsen NV, Aachmann-Andersen NJ, Oturai P, Munch-Andersen T, Bornø A, Hulston C, Holstein-Rathlou NH, Robach P, Lundby C. Erythropoietin down-regulates proximal renal tubular reabsorption and causes a fall in glomerular filtration rate in humans. J Physiol 2010; 589:1273-81. [PMID: 20724370 DOI: 10.1113/jphysiol.2010.194241] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
Recombinant human erythropoietin (rHuEPO) elevates haemoglobin 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. Sixteen healthy males were given rHuEPO for 28 days in doses raising the haematocrit to 48.3±4.1%.Renal clearance studieswith urine collections (N = 8) were done at baseline and at days 4, 11, 29 and 42. Glomerular filtration rate (GFR) was measured by 51Cr-EDTA.Renal clearance of lithium (CLi)was used as an index of proximal tubular outflow and to assess segmental renal tubular handling of sodium and water. rHuEPO-induced increases in haematocrit 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, CLi increased (P < 0.02) indicating a significant 10–16% decrease in absolute proximal reabsorption of sodium and water (APR = GFR − CLi, 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 haematocrit 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. Therefore, treatment with rHuEPO may result in suppression of endogenous EPO synthesis secondary to a decrease in intrarenal oxygen consumption.
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Affiliation(s)
- Niels Vidiendal Olsen
- Department of Neuroanaesthesia, The Neuroscience Centre, Investigation, Rigshospitalet, Copenhagen, Denmark
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