Low dose exogenous erythropoietin elicits an ergogenic effect in standardbred horses.
Abstract: Recombinant human erythropoietin (rhuEPO) causes an increase in red blood cell production and aerobic capacity in other species; however, data are lacking on effects in the horse. Objective: This study tested the hypothesis that rhuEPO administration would alter red cell volume (RCV), aerobic capacity (VO2max) and indices of anaerobic power. Methods: Eight healthy, unfit mares accustomed to the laboratory and experimental protocols were randomly assigned to either a control (CON, n = 4; 3 ml saline 3 times/week for 3 weeks) or EPO group (EPO, n = 4, 50 iu/kg bwt rhuEPO/3 ml saline 3 times/week for 3 weeks). Exercise tests (GXT) were performed on a treadmill (6% incline), 1 week before and 1 week after treatment. The GXT started at 4 m/sec, with a 1 m/sec increase every 60 sec until the horse reached fatigue. Oxygen uptake was measured via an open flow indirect calorimeter. Blood samples were collected before, during (each step) and 2 and 15 min post GXT to measure packed cell volume (PCV), haemoglobin concentration (Hb), blood lactate concentration (LA) and plasma protein concentration (TP). Plasma volume (PV) was measured using Evans Blue dye. Blood volume (BV) and RCV were calculated using PCV from the 8 m/sec step of the GXT. Results: There were no alterations (P>0.05) in any parameters in CON horses. By week 3, EPO produced increases (P0.05) due to decreased PV (-11%, P<0.05). There was a significant increase in velocity at VO2max and LApeak for horses treated with rhuEPO and substantial decrease (P<0.05) in VO2 recovery time when the pretreatment GXT was compared to the post treatment GXT. No differences (P<0.05) were detected for TP, VLA4, run time or Vmax. Conclusions: Low dose rhuEPO administration increases RCV and aerobic capacity without altering anaerobic power. Conclusions: This study demonstrates that rhuEPO enhances aerobic capacity and exercise performance, a question relevant to racing authorities.
Publication Date: 2007-04-04 PubMed ID: 17402424DOI: 10.1111/j.2042-3306.2006.tb05545.xGoogle Scholar: Lookup
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- Journal Article
- Randomized Controlled Trial
- Research Support
- Non-U.S. Gov't
Summary
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This research investigates the effect of a type of hormone, specifically recombinant human erythropoietin (rhuEPO), on the physical performance of horses. The study concludes that administering a low dose of rhuEPO can increase both red cell volume and aerobic capacity, which subsequently enhances the overall performance of the horse, without significantly altering anaerobic power.
Research Methodology
- The study was conducted on eight healthy, unfit mares who were separated into two groups. One group acted as the control, receiving a saline injection, while the other group received the rhuEPO treatment.
- These solutions were administered three times a week for a three-week period. The control group received 3ml of saline, while the rhuEPO group received 50 iu/kg body weight of rhuEPO diluted in 3ml saline.
- The horses’ exercise capacity was tested on a treadmill before and after the treatment period. The treadmills were set at a 6% incline. The exercise test started at a speed of 4m/sec, with a 1m/sec speed increase every minute until the horse reached fatigue. Oxygen consumption was measured using an open flow indirect calorimeter.
- Further, blood samples were collected from the horses at different stages: before, during each step of the exercise, and at two 15 minutes intervals after exercising. These samples were used to measure packed cell volume (PCV), hemoglobin concentration (Hb), blood lactate concentration (LA), and plasma protein concentration (TP). Plasma volume (PV) was also measured using the Evans Blue dye.
Results of the Study
- Analysis of the blood samples and calculations revealed no significant changes in the control group. However, by week three, the horses in the rhuEPO group showed increased resting PCV (37 +/- 2 vs. 51 +/- 2) and Hb (37%).
- The increase in red cell volume (RCV) and max oxygen consumption (VO2max) was 26% and 19% respectively. No change was found in the blood volume, but plasma volume decreased by 11%.
- The horses receiving the rhuEPO treatment also demonstrated a significant increase in velocity at VO2max and LApeak. The time it took for oxygen levels to return to normal after exercise also significantly decreased. No significant differences were found in TP, VLA4, run time or Vmax.
Conclusions
- Administering a low dose of rhuEPO resulted in an increased aerobic capacity and overall exercise performance in the horses.
- The study did not find any alterations to the anaerobic power of the horses. This evidence leads to the conclusion that rhuEPO enhances aerobic endurance without affecting anaerobic strength — a conclusion that might be significant to racing authorities.
Cite This Article
APA
McKeever KH, Agans JM, Geiser S, Lorimer PJ, Maylin GA.
(2007).
Low dose exogenous erythropoietin elicits an ergogenic effect in standardbred horses.
Equine Vet J Suppl(36), 233-238.
https://doi.org/10.1111/j.2042-3306.2006.tb05545.x Publication
Researcher Affiliations
- Equine Science Center, Department of Animal Sciences, Rutgers the State University of New Jersey, 84 Lipman Drive, New Brunswick, New Jersey, 08901-8525, USA.
MeSH Terms
- Animals
- Calorimetry, Indirect / veterinary
- Doping in Sports
- Erythrocyte Volume / drug effects
- Erythrocyte Volume / physiology
- Erythrocyte Volume / veterinary
- Erythropoietin / pharmacology
- Exercise Test / veterinary
- Female
- Hemoglobins / analysis
- Horses / blood
- Horses / physiology
- Oxygen Consumption / drug effects
- Oxygen Consumption / physiology
- Physical Conditioning, Animal / physiology
- Recombinant Proteins
Citations
This article has been cited 3 times.- Senefeld JW, Shepherd JRA, Baker SE, Joyner MJ. Sex-based limits to running speed in the human, horse and dog: The role of sexual dimorphisms. FASEB J 2021 May;35(5):e21562.
- Bishop-Bailey D. Mechanisms governing the health and performance benefits of exercise. Br J Pharmacol 2013 Nov;170(6):1153-66.
- Kiełbik P, Witkowska-Piłaszewicz O. Iron Status in Sport Horses: Is It Important for Equine Athletes?. Int J Mol Sci 2025 Jun 12;26(12).
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