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Sgrò P, Sansone M, Sansone A, Romanelli F, Di Luigi L. Effects of erythropoietin abuse on exercise performance. PHYSICIAN SPORTSMED 2018; 46:105-115. [PMID: 29113535 DOI: 10.1080/00913847.2018.1402663] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
The present review provides a comprehensive overview on the erythropoietic and non-erythropoietic effects of rHuEpo on human sport performance, paying attention to quantifying numerically how rHuEpo affects exercise performance and describing physiological changes regarding the most important exercise variables. Much attention has been paid to treatment schedules, in particular, to assess the effects of microdoses of rHuEpo and the prolonged effects on sport performance following withdrawal. Moreover, the review takes into account non-erythropoietic ergogenic effects of rHuEpo, including cognitive benefits of rHuEpo. A significant increase in both Vo2max and maximal cycling power was evidenced in studies taken into account for this review. rHuEpo, administered at clinical dosage, may have significant effects on haematological values, maximal and submaximal physiological variables, whereas few reports show positive effects on exercise perfomance. However, the influence of micro-dose rHuEpo on endurance performance in athletes is still unclear and further studies are warranted.
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Affiliation(s)
- Paolo Sgrò
- a Department of Movement, Human and Health Sciences, Unit of Endocrinology , Università degli Studi di Roma "Foro Italico" Piazza Lauro de Bosis , Rome , Italy
| | - Massimiliano Sansone
- b Department of Experimental Medicine , "Sapienza" Università di Roma , Rome , Italy
| | - Andrea Sansone
- b Department of Experimental Medicine , "Sapienza" Università di Roma , Rome , Italy
| | - Francesco Romanelli
- b Department of Experimental Medicine , "Sapienza" Università di Roma , Rome , Italy
| | - Luigi Di Luigi
- a Department of Movement, Human and Health Sciences, Unit of Endocrinology , Università degli Studi di Roma "Foro Italico" Piazza Lauro de Bosis , Rome , Italy
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Nielsen J, Christensen AE, Nellemann B, Christensen B. Lipid droplet size and location in human skeletal muscle fibers are associated with insulin sensitivity. Am J Physiol Endocrinol Metab 2017; 313:E721-E730. [PMID: 28743757 DOI: 10.1152/ajpendo.00062.2017] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/21/2017] [Revised: 06/28/2017] [Accepted: 07/18/2017] [Indexed: 11/22/2022]
Abstract
In skeletal muscle, an accumulation of lipid droplets (LDs) in the subsarcolemmal space is associated with insulin resistance, but the underlying mechanism is not clear. We aimed to investigate how the size, number, and location of LDs are associated with insulin sensitivity and muscle fiber types and are regulated by aerobic training and treatment with an erythropoiesis-stimulating agent (ESA) in healthy young untrained men. LD analyses were performed by quantitative transmission electron microscopy, and insulin sensitivity was assessed by a hyperinsulinemic-euglycemic clamp. At baseline, we found that only the diameter (and not the number) of individual subsarcolemmal LDs was negatively associated with insulin sensitivity (R2 = 0.20, P = 0.03, n = 29). Despite 34% (P = 0.004) fewer LDs, the diameter of individual subsarcolemmal LDs was 20% (P = 0.0004) larger in type 2 fibers than in type 1 fibers. Furthermore, aerobic training decreased the size of subsarcolemmal LDs in the type 2 fibers, and ESA treatment lowered the number of both intermyofibrillar and subsarcolemmal LDs in the type 1 fibers. In conclusion, the size of individual subsarcolemmal LDs may be involved in the mechanism by which LDs are associated with insulin resistance in skeletal muscle.
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Affiliation(s)
- Joachim Nielsen
- Department of Sports Science and Clinical Biomechanics, SDU Muscle Research Cluster (SMRC), University of Southern Denmark, Odense M, Denmark;
- Department of Pathology, SDU Muscle Research Cluster (SMRC), Odense University Hospital, Odense C, Denmark; and
| | - Anders E Christensen
- Department of Sports Science and Clinical Biomechanics, SDU Muscle Research Cluster (SMRC), University of Southern Denmark, Odense M, Denmark
| | - Birgitte Nellemann
- Department of Endocrinology and Internal Medicine, NBG/THG, Aarhus University Hospital, Aarhus, Denmark
| | - Britt Christensen
- Department of Endocrinology and Internal Medicine, NBG/THG, Aarhus University Hospital, Aarhus, Denmark
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Christensen B, Nellemann B, Jørgensen JOL, Pedersen SB, Jessen N. Erythropoietin does not activate erythropoietin receptor signaling or lipolytic pathways in human subcutaneous white adipose tissue in vivo. Lipids Health Dis 2016; 15:160. [PMID: 27640183 PMCID: PMC5027120 DOI: 10.1186/s12944-016-0327-z] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2016] [Accepted: 09/06/2016] [Indexed: 01/01/2023] Open
Abstract
Background Erythropoietin (Epo) exerts direct effects on white adipose tissue (WAT) in mice in addition to its erythropoietic effects, and in humans Epo increases resting energy expenditure and affect serum lipid levels, but direct effects of Epo in human WAT have not been documented. We therefore investigated the effects of acute and prolonged Epo exposure on human WAT in vivo. Method Data were obtained from two clinical trials: 1) acute Epo exposure (rHuEpo, 400 IU/kg) followed by WAT biopsies after 1 h and 2) 10 weeks treatment with the erythropoiesis-stimulating agent (ESA) Darbepoietin-alpha. Biopsies were analyzed by PCR for Epo receptor (Epo-R) mRNA. A new and highly specific antibody (A82, Amgen) was used to evaluate the presence of Epo-R by western blot analysis in addition to Epo-R signaling proteins (Akt, STAT5, p70s6k, LYN, and p38MAPK), activation of lipolytic pathways (ATGL, HSL, CGI-58, G0S2, Perilipin, Cidea, Cidec, AMPK, and ACC), and mitochondrial biogenesis (VDAC, HSP90, PDH, and SDHA). Results No evidence of in vivo activation of the Epo-R in WAT could be documented despite detectable levels of Epo-R mRNA. Conclusion Thus, in contradiction to animal studies, Epo treatment within a physiological relevant range in humans does not exert direct effects in a subcutaneous WAT.
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Affiliation(s)
- Britt Christensen
- Department of Endocrinology and Internal Medicine, NBG/THG, Aarhus University Hospital, Nørrebrogade 44, 8000, Aarhus C, Denmark. .,Research Laboratory for Biochemical Pathology, Institute for Clinical Medicine, Aarhus University Hospital, Aarhus, Denmark.
| | - Birgitte Nellemann
- Department of Endocrinology and Internal Medicine, NBG/THG, Aarhus University Hospital, Nørrebrogade 44, 8000, Aarhus C, Denmark
| | - Jens Otto L Jørgensen
- Department of Endocrinology and Internal Medicine, NBG/THG, Aarhus University Hospital, Nørrebrogade 44, 8000, Aarhus C, Denmark
| | - Steen B Pedersen
- Department of Endocrinology and Internal Medicine, NBG/THG, Aarhus University Hospital, Nørrebrogade 44, 8000, Aarhus C, Denmark
| | - Niels Jessen
- Research Laboratory for Biochemical Pathology, Institute for Clinical Medicine, Aarhus University Hospital, Aarhus, Denmark.,Department of Molecular Medicine, Aarhus University Hospital, Aarhus, Denmark
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Mazzolari R, Papaioannou KG. Satellite cells: erythropoietin treatment and endurance training. J Physiol 2016; 594:5045-6. [PMID: 27629077 DOI: 10.1113/jp272720] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Affiliation(s)
- Raffaele Mazzolari
- Division of Exercise Science and Sports Medicine, Department of Human Biology, Faculty of Health Science, University of Cape Town, Cape Town, South Africa.
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Sieljacks P, Thams L, Nellemann B, Larsen MS, Vissing K, Christensen B. Comparative Effects of Aerobic Training and Erythropoietin on Oxygen Uptake in Untrained Humans. J Strength Cond Res 2016; 30:2307-17. [DOI: 10.1519/jsc.0000000000001314] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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Hoedt A, Christensen B, Nellemann B, Mikkelsen UR, Hansen M, Schjerling P, Farup J. Satellite cell response to erythropoietin treatment and endurance training in healthy young men. J Physiol 2015; 594:727-43. [PMID: 26607845 DOI: 10.1113/jp271333] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2015] [Accepted: 11/18/2015] [Indexed: 11/08/2022] Open
Abstract
KEY POINT Erythropoietin (Epo) treatment may induce myogenic differentiation factor (MyoD) expression and prevent apoptosis in satellite cells (SCs) in murine and in vitro models. Endurance training stimulates SC proliferation in vivo in murine and human skeletal muscle. In the present study, we show, in human skeletal muscle, that treatment with an Epo-stimulating agent (darbepoetin-α) in vivo increases the content of MyoD(+) SCs in healthy young men. Moreover, we report that Epo receptor mRNA is expressed in adult human SCs, suggesting that Epo may directly target SCs through ligand-receptor interaction. Moreover, endurance training, but not Epo treatment, increases the SC content in type II myofibres, as well as the content of MyoD(+) SCs. Collectively, our results suggest that Epo treatment can regulate human SCs in vivo, supported by Epo receptor mRNA expression in human SCs. In effect, long-term Epo treatment during disease conditions involving anaemia may impact SCs and warrants further investigation. Satellite cell (SC) proliferation is observed following erythropoitin treatment in vitro in murine myoblasts and endurance training in vivo in human skeletal muscle. The present study aimed to investigate the effects of prolonged erythropoiesis-stimulating agent (ESA; darbepoetin-α) treatment and endurance training, separately and combined, on SC quantity and commitment in human skeletal muscle. Thirty-five healthy, untrained men were randomized into four groups: sedentary-placebo (SP, n = 9), sedentary-ESA (SE, n = 9), training-placebo (TP, n = 9) or training-ESA (TE, n = 8). ESA/placebo was injected once weekly and training consisted of ergometer cycling three times a week for 10 weeks. Prior to and following the intervention period, blood samples and muscle biopsies were obtained and maximal oxygen uptake (V̇O2, max) was measured. Immunohistochemical analyses were used to quantify fibre type specific SCs (Pax7(+)), myonuclei and active SCs (Pax7(+)/MyoD(+)). ESA treatment led to elevated haematocrit, whereas endurance training increased V̇O2, max. Endurance training led to an increase in SCs associated with type II fibres (P < 0.05), whereas type I fibres showed no changes. Both ESA treatment and endurance training increased Pax7(+)/MyoD(+) cells, whereas only ESA treatment increased the total content of MyoD(+) cells. Epo-R mRNA presence in adult SC was tested with real-time RT-PCR using fluorescence-activated cell sorting (CD56(+)/CD45(-)/CD31(-)) to isolate cells from a human rectus abdominis muscle and was found to be considerably higher than in whole muscle. In conclusion, endurance training and ESA treatment may separately stimulate SC commitment to the myogenic program. Furthermore, ESA-treatment may alter SC activity by direct interaction with the Epo-R expressed on SCs.
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Affiliation(s)
- Andrea Hoedt
- Section for Sports Science, Department of Public Health, Aarhus University, Aarhus, Denmark
| | - Britt Christensen
- Department of Endocrinology and Internal Medicine, NBG/THG, Aarhus University Hospital, Aarhus, Denmark.,Medical Research Laboratories, Institute for Clinical Medicine, Aarhus University Hospital, Aarhus, Denmark
| | - Birgitte Nellemann
- Department of Endocrinology and Internal Medicine, NBG/THG, Aarhus University Hospital, Aarhus, Denmark.,Medical Research Laboratories, Institute for Clinical Medicine, Aarhus University Hospital, Aarhus, Denmark
| | - Ulla Ramer Mikkelsen
- Section for Sports Science, Department of Public Health, Aarhus University, Aarhus, Denmark.,Institute of Sports Medicine, Department of Orthopaedic Surgery M, Bispebjerg Hospital and Centre for Healthy Aging, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Mette Hansen
- Section for Sports Science, Department of Public Health, Aarhus University, Aarhus, Denmark
| | - Peter Schjerling
- Institute of Sports Medicine, Department of Orthopaedic Surgery M, Bispebjerg Hospital and Centre for Healthy Aging, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Jean Farup
- Section for Sports Science, Department of Public Health, Aarhus University, Aarhus, Denmark
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Christensen B, Ludvigsen M, Nellemann B, Kopchick JJ, Honoré B, Jørgensen JOL. Serum proteomic changes after randomized prolonged erythropoietin treatment and/or endurance training: detection of novel biomarkers. PLoS One 2015; 10:e0117119. [PMID: 25679398 PMCID: PMC4332672 DOI: 10.1371/journal.pone.0117119] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2014] [Accepted: 12/12/2014] [Indexed: 01/09/2023] Open
Abstract
INTRODUCTION Despite implementation of the biological passport to detect erythropoietin abuse, a need for additional biomarkers remains. We used a proteomic approach to identify novel serum biomarkers of prolonged erythropoiesis-stimulating agent (ESA) exposure (Darbepoietin-α) and/or aerobic training. TRIAL DESIGN Thirty-six healthy young males were randomly assigned to the following groups: Sedentary-placebo (n = 9), Sedentary-ESA (n = 9), Training-placebo (n = 10), or Training-ESA (n = 8). They were treated with placebo/Darbepoietin-α subcutaneously once/week for 10 weeks followed by a 3-week washout period. Training consisted of supervised biking 3/week for 13 weeks at the highest possible intensity. Serum was collected at baseline, week 3 (high dose Darbepoietin-α), week 10 (reduced dose Darbepoietin-α), and after a 3-week washout period. METHODS Serum proteins were separated according to charge and molecular mass (2D-gel electrophoresis). The identity of proteins from spots exhibiting altered intensity was determined by mass spectrometry. RESULTS Six protein spots changed in response to Darbepoietin-α treatment. Comparing all 4 experimental groups, two protein spots (serotransferrin and haptoglobin/haptoglobin related protein) showed a significant response to Darbepoietin-α treatment. The haptoglobin/haptoglobin related protein spot showed a significantly lower intensity in all subjects in the training-ESA group during the treatment period and increased during the washout period. CONCLUSION An isoform of haptoglobin/haptoglobin related protein could be a new anti-doping marker and merits further research. TRIAL REGISTRATION ClinicalTrials.gov NCT01320449.
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Affiliation(s)
- Britt Christensen
- Department of Endocrinology and Internal Medicine, Aarhus University Hospital, Aarhus, Denmark; Medical Research Laboratories, Aarhus University, Aarhus, Denmark; Research Laboratory for Biochemical Pathology, Institute for Clinical Medicine, Aarhus University Hospital, Aarhus, Denmark
| | - Maja Ludvigsen
- Department of Biomedicine, Aarhus University, Aarhus, Denmark
| | - Birgitte Nellemann
- Department of Endocrinology and Internal Medicine, Aarhus University Hospital, Aarhus, Denmark; Medical Research Laboratories, Aarhus University, Aarhus, Denmark
| | - John J Kopchick
- Edison Biotechnology Institute Ohio University, Athens, Ohio, United States of America; Department of Biomedical Sciences, Heritage College of Osteopathic Medicine, Ohio University, Athens, Ohio, United States of America
| | - Bent Honoré
- Department of Biomedicine, Aarhus University, Aarhus, Denmark
| | - Jens Otto L Jørgensen
- Department of Endocrinology and Internal Medicine, Aarhus University Hospital, Aarhus, Denmark
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Larsen MS, Vissing K, Thams L, Sieljacks P, Dalgas U, Nellemann B, Christensen B. Erythropoietin administration alone or in combination with endurance training affects neither skeletal muscle morphology nor angiogenesis in healthy young men. Exp Physiol 2014; 99:1409-20. [PMID: 25128327 DOI: 10.1113/expphysiol.2014.080606] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
The aim was to investigate the ability of an erythropoiesis-stimulating agent (ESA), alone or in combination with endurance training, to induce changes in human skeletal muscle fibre and vascular morphology. In a comparative study, 36 healthy untrained men were randomly dispersed into the following four groups: sedentary-placebo (SP, n = 9); sedentary-ESA (SE, n = 9); training-placebo (TP, n = 10); or training-ESA (TE, n = 8). The ESA or placebo was injected once weekly. Training consisted of progressive bicycling three times per week for 10 weeks. Before and after the intervention period, muscle biopsies and magnetic resonance images were collected from the thigh muscles, blood was collected, body composition measured and endurance exercise performance evaluated. The ESA treatment (SE and TE) led to elevated haematocrit, and both ESA treatment and training (SE, TP and TE) increased maximal O2 uptake. With regard to skeletal muscle morphology, TP alone exhibited increases in whole-muscle cross-sectional area and fibre diameter of all fibre types. Also exclusively for TP was an increase in type IIa fibres and a corresponding decrease in type IIx fibres. Furthermore, an overall training effect (TP and TE) was statistically demonstrated in whole-muscle cross-sectional area, muscle fibre diameter and type IIa and type IIx fibre distribution. With regard to muscle vascular morphology, TP and TE both promoted a rise in capillary to muscle fibre ratio, with no differences between the two groups. There were no effects of ESA treatment on any of the muscle morphological parameters. Despite the haematopoietic effects of ESA, we provide novel evidence that endurance training rather than ESA treatment induces adaptational changes in angiogenesis and muscle morphology.
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Affiliation(s)
- Mads S Larsen
- Section of Sports Science, Institute of Public Health, Aarhus University, Aarhus, Denmark
| | - Kristian Vissing
- Section of Sports Science, Institute of Public Health, Aarhus University, Aarhus, Denmark
| | - Line Thams
- Section of Sports Science, Institute of Public Health, Aarhus University, Aarhus, Denmark
| | - Peter Sieljacks
- Section of Sports Science, Institute of Public Health, Aarhus University, Aarhus, Denmark
| | - Ulrik Dalgas
- Section of Sports Science, Institute of Public Health, Aarhus University, Aarhus, Denmark
| | - Birgitte Nellemann
- Department of Endocrinology and Internal Medicine, Aarhus University Hospital, Aarhus, Denmark
| | - Britt Christensen
- Section of Sports Science, Institute of Public Health, Aarhus University, Aarhus, Denmark Department of Endocrinology and Internal Medicine, Aarhus University Hospital, Aarhus, Denmark
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