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Breenfeldt Andersen A, Graae J, Bejder J, Bonne TC, Seier S, Debertin M, Eibye K, Hostrup M, Nordsborg NB. Microdoses of Recombinant Human Erythropoietin Enhance Time Trial Performance in Trained Males and Females. Med Sci Sports Exerc 2023; 55:311-321. [PMID: 36317927 DOI: 10.1249/mss.0000000000003052] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
PURPOSE We investigated the effects of recombinant human erythropoietin (rHuEPO) administration on exercise endurance, maximal aerobic performance, and total hemoglobin mass (tHb). We hypothesized that frequent, small intravenous injections of epoetin β would increase time trial performance, peak oxygen uptake (V̇O 2peak ), and tHb in both males and females. METHODS We included 48 healthy, recreational to trained males ( n = 24, mean ± SD V̇O 2peak = 55 ± 5 mL O 2 ·kg -1 ⋅min -1 ) and females ( n = 24; V̇O 2peak of 46 ± 4 mL O 2 ·kg -1 ⋅min -1 ) in a counterbalanced, double-blind, randomized, placebo-controlled study design stratified by sex. Time trial performance, V̇O 2peak , and tHb were determined before and after intravenous injections of either rHuEPO (9 IU·kg bw -1 epoetin β) or saline (0.9% NaCl) three times weekly for 4 wk. RESULTS A time-treatment effect ( P < 0.05) existed for time trial performance. Within the rHuEPO group, mean power output increased by 4.1% ± 4.2% ( P < 0.001). Likewise, a time-treatment effect ( P < 0.001) existed for V̇O 2peak , where the rHuEPO group improved V̇O 2peak and peak aerobic power by 4.2% ± 6.1% ( P < 0.001) and 2.9% ± 4.0% ( P < 0.01), respectively. A time-treatment effect ( P < 0.001) existed for tHb, where the rHuEPO group increased tHb by 6.7% ± 3.4% ( P < 0.001). A main effect of "sex" alone was also evident ( P < 0.001), but no sex-specific interactions were found. No changes were observed in the placebo group for mean power output, V̇O 2peak , peak aerobic power, or tHb. CONCLUSIONS Microdoses with intravenous rHuEPO provide a sufficient erythropoietic stimuli to augment tHb and enhance aerobic-dominated performance in both trained males and females.
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Affiliation(s)
| | - Jonathan Graae
- Department of Nutrition, Exercise and Sports (NEXS), University of Copenhagen, Copenhagen, DENMARK
| | - Jacob Bejder
- Department of Nutrition, Exercise and Sports (NEXS), University of Copenhagen, Copenhagen, DENMARK
| | - Thomas C Bonne
- Department of Nutrition, Exercise and Sports (NEXS), University of Copenhagen, Copenhagen, DENMARK
| | - Søren Seier
- Department of Nutrition, Exercise and Sports (NEXS), University of Copenhagen, Copenhagen, DENMARK
| | - Maren Debertin
- Department of Nutrition, Exercise and Sports (NEXS), University of Copenhagen, Copenhagen, DENMARK
| | - Kasper Eibye
- Department of Nutrition, Exercise and Sports (NEXS), University of Copenhagen, Copenhagen, DENMARK
| | - Morten Hostrup
- Department of Nutrition, Exercise and Sports (NEXS), University of Copenhagen, Copenhagen, DENMARK
| | - Nikolai B Nordsborg
- Department of Nutrition, Exercise and Sports (NEXS), University of Copenhagen, Copenhagen, DENMARK
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Huang YC, Cheng ML, Tang HY, Huang CY, Chen KM, Wang JS. Eccentric Cycling Training Improves Erythrocyte Antioxidant and Oxygen Releasing Capacity Associated with Enhanced Anaerobic Glycolysis and Intracellular Acidosis. Antioxidants (Basel) 2021; 10:antiox10020285. [PMID: 33668606 PMCID: PMC7918820 DOI: 10.3390/antiox10020285] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2021] [Revised: 02/09/2021] [Accepted: 02/10/2021] [Indexed: 11/20/2022] Open
Abstract
The antioxidant capacity of erythrocytes protects individuals against the harmful effects of oxidative stress. Despite improved hemodynamic efficiency, the effect of eccentric cycling training (ECT) on erythrocyte antioxidative capacity remains unclear. This study investigates how ECT affects erythrocyte antioxidative capacity and metabolism in sedentary males. Thirty-six sedentary healthy males were randomly assigned to either concentric cycling training (CCT, n = 12) or ECT (n = 12) at 60% of the maximal workload for 30 min/day, 5 days/week for 6 weeks or to a control group (n = 12) that did not receive an exercise intervention. A graded exercise test (GXT) was performed before and after the intervention. Erythrocyte metabolic characteristics and O2 release capacity were determined by UPLC-MS and high-resolution respirometry, respectively. An acute GXT depleted Glutathione (GSH), accumulated Glutathione disulfide (GSSG), and elevated the GSSG/GSH ratio, whereas both CCT and ECT attenuated the extent of the elevated GSSG/GSH ratio caused by a GXT. Moreover, the two exercise regimens upregulated glycolysis and increased glucose consumption and lactate production, leading to intracellular acidosis and facilitation of O2 release from erythrocytes. Both CCT and ECT enhance antioxidative capacity against severe exercise-evoked circulatory oxidative stress. Moreover, the two exercise regimens activate erythrocyte glycolysis, resulting in lowered intracellular pH and enhanced O2 released from erythrocytes.
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Affiliation(s)
- Yu-Chieh Huang
- Department of Physical Therapy, College of Medical and Health Science, Asia University, Taichung 413, Taiwan;
| | - Mei-Ling Cheng
- Metabolomics Core Laboratory, Healthy Aging Research Center, Chang Gung University, Taoyuan 333, Taiwan; (M.-L.C.); (H.-Y.T.)
- Clinical Metabolomics Core Laboratory, Chang Gung Memorial Hospital, Taoyuan 333, Taiwan
- Department of Biomedical Sciences, College of Medicine, Chang Gung University, Taoyuan 333, Taiwan
| | - Hsiang-Yu Tang
- Metabolomics Core Laboratory, Healthy Aging Research Center, Chang Gung University, Taoyuan 333, Taiwan; (M.-L.C.); (H.-Y.T.)
| | - Chi-Yao Huang
- Healthy Aging Research Center, Graduate Institute of Rehabilitation Science, Medical Collage, Chang Gung University, Taoyuan 333, Taiwan; (C.-Y.H.); (K.-M.C.)
| | - Kuan-Ming Chen
- Healthy Aging Research Center, Graduate Institute of Rehabilitation Science, Medical Collage, Chang Gung University, Taoyuan 333, Taiwan; (C.-Y.H.); (K.-M.C.)
| | - Jong-Shyan Wang
- Healthy Aging Research Center, Graduate Institute of Rehabilitation Science, Medical Collage, Chang Gung University, Taoyuan 333, Taiwan; (C.-Y.H.); (K.-M.C.)
- Heart Failure Center, Department of Physical Medicine and Rehabilitation, Keelung Chang Gung Memorial Hospital, Keelung 204, Taiwan
- Research Center for Chinese Herbal Medicine, College of Human Ecology, Chang Gung University of Science and Technology, Taoyuan 333, Taiwan
- Correspondence: ; Tel.: +886-3-2118800 (ext. 5748); Fax: +886+886-3-2118700
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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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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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Caillaud C, Connes P, Ben Saad H, Mercier J. Erythropoietin enhances whole body lipid oxidation during prolonged exercise in humans. J Physiol Biochem 2015; 71:9-16. [DOI: 10.1007/s13105-014-0374-8] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2014] [Accepted: 12/16/2014] [Indexed: 01/29/2023]
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The Effect of Sodium Bicarbonate Supplement on Lactic Acid, Ammonia and the Performance of 400 Meters Male Runners. BALTIC JOURNAL OF HEALTH AND PHYSICAL ACTIVITY 2012. [DOI: 10.2478/v10131-012-0009-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
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Wahl P, Yue Z, Zinner C, Bloch W, Mester J. A mathematical model for lactate transport to red blood cells. J Physiol Sci 2011; 61:93-102. [PMID: 21181323 PMCID: PMC10717242 DOI: 10.1007/s12576-010-0125-8] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2010] [Accepted: 11/30/2010] [Indexed: 10/18/2022]
Abstract
A simple mathematical model for the transport of lactate from plasma to red blood cells (RBCs) during and after exercise is proposed based on our experimental studies for the lactate concentrations in RBCs and in plasma. In addition to the influx associated with the plasma-to-RBC lactate concentration gradient, it is argued that an efflux must exist. The efflux rate is assumed to be proportional to the lactate concentration in RBCs. This simple model is justified by the comparison between the model-predicted results and observations: For all 33 cases (11 subjects and 3 different warm-up conditions), the model-predicted time courses of lactate concentrations in RBC are generally in good agreement with observations, and the model-predicted ratios between lactate concentrations in RBCs and in plasma at the peak of lactate concentration in RBCs are very close to the observed values. Two constants, the influx rate coefficient C (1) and the efflux rate coefficient C (2), are involved in the present model. They are determined by the best fit to observations. Although the exact electro-chemical mechanism for the efflux remains to be figured out in the future research, the good agreement of the present model with observations suggests that the efflux must get stronger as the lactate concentration in RBCs increases. The physiological meanings of C (1) and C (2) as well as their potential applications are discussed.
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Affiliation(s)
- Patrick Wahl
- Institute of Training Science and Sport Informatics, German Sport University Cologne, Am Sportpark Müngersdorf 6, 50933, Cologne, Germany.
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8
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Alterations of blood rheology during and after exercise are both consequences and modifiers of body's adaptation to muscular activity. Sci Sports 2007. [DOI: 10.1016/j.scispo.2007.09.010] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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9
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Juel C, Thomsen JJ, Rentsch RL, Lundby C. Effects of prolonged recombinant human erythropoietin administration on muscle membrane transport systems and metabolic marker enzymes. Eur J Appl Physiol 2007; 102:41-4. [PMID: 17882450 DOI: 10.1007/s00421-007-0567-8] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/03/2007] [Indexed: 11/24/2022]
Abstract
Adaptations to chronic hypoxia involve changes in membrane transport proteins. The underlying mechanism of this response may be related to concomitant occurring changes in erythropoietin (Epo) levels. We therefore tested the direct effects of recombinant human erythropoietin (rHuEpo) treatment on the expression of muscle membrane transport proteins. Likewise, improvements in performance may involve upregulation of metabolic enzymes. Since Epo is known to augment performance we tested the effect of rHuEpo on some marker enzymes that are related to aerobic capacity. For these purposes eight subjects received 5,000 IU rHuEpo every second day for 14 days, and subsequently a single dose of 5,000 IU weekly for 12 weeks. Muscle biopsies were obtained before and after 14 weeks of rHuEpo treatment. The treatment increased hematocrit (from 44.7 to 48.8%), maximal oxygen uptake by 8.1%, and submaximal performance by approximately 54%. Membrane transport systems and carbonic anhydrases involved in pH regulation remained unchanged. Of the Na(+), K(+)-pump isoforms only the density of the alpha2 subunit was decreased (by 22%) after treatment. The marker enzymes cytochrom c and hexokinase remained unchanged with the treatment. In conclusion, changes in muscle membrane transport proteins and selected muscle enzymes do not contribute to the Epo-induced improvement in performance.
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Affiliation(s)
- C Juel
- Copenhagen Muscle Research Centre, Department of Molecular Biology, University of Copenhagen, Copenhagen, Denmark.
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10
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Kohler G, Rost F, Seelig J. Simultaneous separation of intracellular and extracellular lactate NMR signals of human erythrocytes. Magn Reson Med 2007; 58:213-7. [PMID: 17654594 DOI: 10.1002/mrm.21309] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Intracellular/extracellular lactate (Lac) distribution has been determined before in human and animal erythrocytes (red blood cells [RBCs]) with various methods. However, all previous methods determine intra- and extracellular Lac separately or indirectly. Now, (13)C-NMR spectroscopy has been used to monitor intra- and extracellular Lac simultaneously in intact RBCs. Isolated human RBCs were incubated with [3-(13)C]-Lac, [3-(13)C]-pyruvate (Pyr), and [1-(13)C]-glucose (Gluc). A distortionless enhancement by polarization transfer (DEPT) sequence was used (TR = 3.3 s, N = 128) to monitor the (13)C-NMR resonances in both compartments. The intra- and extracellular methyl group resonances of Lac and Pyr were clearly separated by 9.6 Hz and 7.0 Hz, respectively, under normoxic conditions due to the RBC chemical-shift effect. The results show that the chemical-shift effect of RBCs is convenient to monitor intra- and extracellular Lac simultaneously in intact RBCs under normoxic conditions.
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Affiliation(s)
- Götz Kohler
- Biozentrum, Department of Biophysical Chemistry, University of Basel, Basel, Switzerland.
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11
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Rentsch RL, Damsgaard R, Lundby C, Juel C. Effects of darbepoetin injections on erythrocyte membrane transport protein expressions in humans. J Appl Physiol (1985) 2006; 101:164-8. [PMID: 16575022 DOI: 10.1152/japplphysiol.01376.2005] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The present study investigated the effects of injected darbepoetin [novel erythropoietin stimulating protein (NESP)] on the density of three erythrocyte membrane transport proteins: the lactate-H+ cotransporter (monocarboxylate transporter 1), the chloride/bicarbonate exchanger 1 (anion exchanger 1), and the water channel aquaporin 1. Thirteen subjects were injected with NESP once a week for 4 wk. Blood samples were obtained before, during, and after the injection period, and the erythrocyte transport proteins were determined by Western blotting. The NESP injections induced a transient increase in hematocrit, red cell volume, and reticulocyte fraction. The density of aquaporin 1 protein was higher (maximal increase +59%) ( P < 0.01) during the injection period compared with the preinjection value and lower ( P < 0.01) after the injection period. The density of anion exchanger 1 protein was higher (maximal increase +15%) ( P < 0.05) during the injection period compared with the preinjection value and tended ( P = 0.06) to be lower after the injection period than before the injection period. The density of the erythrocyte monocarboxylate transporter 1 protein was higher (maximal increase +43%) ( P < 0.05) during the injection period than in the preinjection period. Age separation experiments using self-creating Percoll gradients demonstrated a higher density of membrane transport proteins in young red blood cells. These data suggest that the NESP-induced increase in membrane transport proteins is caused by a higher fraction of newly formed erythrocytes (and reticulocytes), which have a higher density of membrane transport proteins. However, increased incorporation of membrane proteins during erythrocyte formation may also be involved. We suggest that NESP improves the quality of erythrocyte membrane transport through these mechanisms.
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Affiliation(s)
- Rikke Louise Rentsch
- Copenhagen Muscle Research Centre, Institute of Molecular Biology and Physiology, The August Krogh Bldg., University of Copenhagen, Universitetsparken 13, DK-2100 Copenhagen, Denmark
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Sara F, Fagnété S, Connes P, Philippe C, Hue O, Olivier H, Montout-Hedreville M, Mona MH, Etienne-Julan M, Maryse EJ, Hardy-Dessources MD, Marie-Dominique HD. Faster lactate transport across red blood cell membrane in sickle cell trait carriers. J Appl Physiol (1985) 2005; 100:427-32. [PMID: 16239612 DOI: 10.1152/japplphysiol.00771.2005] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The physical and physiological behavior of sickle cell trait carriers (AS) is somewhat equivocal under strenuous conditions, although this genetic abnormality is generally considered to be a benign disorder. The occurrence of incidents and severe injuries in AS during exercise might be explained, in part, by the lactic acidosis due to a greater lactate influx into AS red blood cells (RBCs). In the present study, the RBC lactate transport activity via the different pathways was compared between AS and individuals with normal hemoglobin (AA). Sixteen Caribbean students, nine AS and seven AA, performed a progressive and maximal exercise test to determine maximal oxygen consumption. Blood samples were obtained at rest to assess haematological parameters and RBC lactate transport activity. Lactate influxes [total lactate influx and monocarboxylate transporter (MCT-1)-mediated lactate influx] into erythrocytes were measured at four external [14C]-labeled lactate concentrations (1.6, 8.1, 41, and 81.1 mM). The two groups had similar maximal oxygen consumption. Total lactate influx and lactate influx via the MCT-1 pathway were significantly higher in AS compared with AA at 1.6, 41, and 81.1 mM. The maximal lactate transport capacity for MCT-1 was higher in AS than in AA. Although AS and AA had the same maximal aerobic physical fitness, the RBCs from the sickle cell trait carriers took up more lactate at low and high concentrations than the RBCs from AA individuals. The higher MCT-1 maximal lactate transport capacity found in AS suggests greater content or greater activity of MCT-1 in AS RBC membranes.
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Affiliation(s)
- Fagnété Sara
- Laboratoire Adaptation au Climat Tropical, Exercice et Société Unité Propre de Recherche de l'Enseignment Supérieur-Equipe d'Accueil 3596, Université des Antilles et de la Guyane, Campus de Fouillole, Pointe-à- Pitre Cedex, Guadeloupe
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13
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Pösö A, Puolanne E. Carbohydrate metabolism in meat animals. Meat Sci 2005; 70:423-34. [DOI: 10.1016/j.meatsci.2004.12.017] [Citation(s) in RCA: 74] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2004] [Revised: 11/26/2004] [Accepted: 12/01/2004] [Indexed: 10/25/2022]
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Pattillo RE, Gladden LB. Red blood cell lactate transport in sickle disease and sickle cell trait. J Appl Physiol (1985) 2005; 99:822-7. [PMID: 15890755 DOI: 10.1152/japplphysiol.00235.2005] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
This study determined and compared rates and mechanisms of lactate transport in red blood cells (RBCs) of persons with 1) sickle cell disease (HbSS), 2) sickle cell trait (HbAS), and 3) a control group (HbAA). Blood samples were drawn from 30 African-American volunteers (10 HbSS, 10 HbAS, 10 HbAA). Lactate influx into RBCs was measured by using [14C]lactate at six (2, 5, 10, 15, 25, and 40 mM) unlabeled lactate concentrations. The monocarboxylate transporter pathway was blocked by p-chloromercuriphenylsulfonic acid to determine its percent contribution to total lactate influx. Generally, total lactate influx into RBCs from the HbSS group was significantly greater than influx into RBCs from HbAS or HbAA, with no difference between HbAS and HbAA. Faster influx into HbSS RBCs was attributed to increased monocarboxylate transporter activity [increased apparent Vmax (V'max)]. V'max (4.7 +/- 0.6 micromol x ml(-1) x min(-1)) for HbSS RBCs was significantly greater than V'max of HbAS RBCs (2.9 +/- 1.5 micromol x ml(-1) x min(-1)) and HbAA RBCs (2.0 +/- 0.5 micromol x ml(-1) x min(-1)). Km (42.8 +/- 8 mM) for HbSS RBCs was significantly greater than Km (27 +/- 12 mM) for HbAA RBCs. We suspect that elevated erythropoietin levels in response to chronic anemia and/or pharmacological treatment (erythropoietin injections, hydroxyurea ingestion) is the underlying mechanism for increased lactate transport capacity in HbSS RBCs.
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Connes P, Bouix D, Py G, Caillaud C, Kippelen P, Brun JF, Varray A, Prefaut C, Mercier J. Does exercise-induced hypoxemia modify lactate influx into erythrocytes and hemorheological parameters in athletes? J Appl Physiol (1985) 2004; 97:1053-8. [PMID: 15121747 DOI: 10.1152/japplphysiol.00993.2003] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
This study investigated 1) red blood cells (RBC) rigidity and 2) lactate influxes into RBCs in endurance-trained athletes with and without exercise-induced hypoxemia (EIH). Nine EIH and six non-EIH subjects performed a submaximal steady-state exercise on a cyclo-ergometer at 60% of maximal aerobic power for 10 min, followed by 15 min at 85% of maximal aerobic power. At rest and at the end of exercise, arterialized blood was sampled for analysis of arterialized pressure in oxygen, and venous blood was drawn for analysis of plasma lactate concentrations and hemorheological parameters. Lactate influxes into RBCs were measured at three labeled [U-14C]lactate concentrations (1.6, 8.1, and 41 mM) on venous blood sampled at rest. The EIH subjects had higher maximal oxygen uptake than non-EIH ( P < 0.05). Total lactate influx was significantly higher in RBCs from EIH compared with non-EIH subjects at 8.1 mM (1,498.1 ± 87.8 vs. 1,035.9 ± 114.8 nmol·ml−1·min−1; P < 0.05) and 41 mM (2,562.0 ± 145.0 vs. 1,618.1 ± 149.4 nmol·ml−1·min−1; P < 0.01). Monocarboxylate transporter-1-mediated lactate influx was also higher in EIH at 8.1 mM ( P < 0.05) and 41 mM ( P < 0.01). The drop in arterial oxygen partial pressure was negatively correlated with total lactate influx measured at 8.1 mM ( r = −0.82, P < 0.05) and 41 mM ( r = −0.84, P < 0.05) in the two groups together. Plasma lactate concentrations and hemorheological data were similar in the two groups at rest and at the end of exercise. The results showed higher monocarboxylate transporter-1-mediated lactate influx in the EIH subjects and suggested that EIH could modify lactate influx into erythrocyte. However, higher lactate influx in EIH subjects was not accompanied by an increase in RBC rigidity.
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Affiliation(s)
- Philippe Connes
- EA 2991 Sport, Performance et Santé, Faculté des Sciences du Sport, Université de Montpellier, 34295 Montpellier, France
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