The biochemistry of drugs and doping methods used to enhance aerobic sport performance

2008 ◽  
Vol 44 ◽  
pp. 63-84 ◽  
Author(s):  
Chris E. Cooper
Keyword(s):  
Oxygen Uptake ◽  
Oxygen Content ◽  
Oxygen Delivery ◽  
Sport Performance ◽  
Blood Substitutes ◽  
Altitude Training ◽  
Blood Oxygen ◽  
Oxygen Carriers ◽  
Sports Performance ◽  
Blood Doping

Optimum performance in aerobic sports performance requires an efficient delivery to, and consumption of, oxygen by the exercising muscle. It is probable that maximal oxygen uptake in the athlete is multifactorial, being shared between cardiac output, blood oxygen content, muscle blood flow, oxygen diffusion from the blood to the cell and mitochondrial content. Of these, raising the blood oxygen content by raising the haematocrit is the simplest acute method to increase oxygen delivery and improve sport performance. Legal means of raising haematocrit include altitude training and hypoxic tents. Illegal means include blood doping and the administration of EPO (erythropoietin). The ability to make EPO by genetic means has resulted in an increase in its availability and use, although it is probable that recent testing methods may have had some impact. Less widely used illegal methods include the use of artificial blood oxygen carriers (the so-called ‘blood substitutes’). In principle these molecules could enhance aerobic sports performance; however, they would be readily detectable in urine and blood tests. An alternative to increasing the blood oxygen content is to increase the amount of oxygen that haemoglobin can deliver. It is possible to do this by using compounds that right-shift the haemoglobin dissociation curve (e.g. RSR13). There is a compromise between improving oxygen delivery at the muscle and losing oxygen uptake at the lung and it is unclear whether these reagents would enhance the performance of elite athletes. However, given the proven success of blood doping and EPO, attempts to manipulate these pathways are likely to lead to an ongoing battle between the athlete and the drug testers.

Abstract 190: Repeated Doses of Dodecafluoropentane Emulsion Provide Neuroprotection Up to 24 Hours Following Cerebral Artery Occlusion in Rabbits

Stroke ◽  
2013 ◽  
Vol 44 (suppl_1) ◽  
Author(s):  
Sean D Woods ◽  
Robert D Skinner ◽  
Aliza T Brown ◽  
Aaron M Ricca ◽  
Jennifer L Johnson ◽  
...  
Keyword(s):  
Cerebral Artery ◽  
Oxygen Delivery ◽  
Infarct Volume ◽  
Rabbit Model ◽  
Artery Occlusion ◽  
Blood Substitutes ◽  
Hypoxic Cell ◽  
Oxygen Carriers ◽  
Repeated Doses ◽  
Cerebral Artery Occlusion

Introduction: Neuroprotective strategies in ischemic stroke include oxygen delivery to sustain penumbra and prevent hypoxic cell death. Hyperbaric oxygen, blood substitutes, and liquid fluorocarbon-based oxygen carriers have often failed in treatment of stroke and other ischemic disorders. Dodecafluoropentane emulsion (DDFPe, boiling point 29°C) shifts to quasi-gas phase at body temperature, which allows absorption and transportation of very high levels of oxygen. Exceptionally small particle size, 250-300 nm, may allow oxygen delivery even through occluded vessels, by diffusion into hypoxic tissue unreachable by whole blood. In a preliminary stroke study in rabbits, DDFPe reduced infarct volumes in all experimental groups by 80% or more. Hypothesis: Repeated doses of DDFPe can reduce infarct volume for up to 24 hours after permanent cerebral artery occlusion in rabbits. Methods: New Zealand White rabbits (N=55) received cerebral angiography from a femoral artery approach. Embolic microspheres (diameter=700-900 μm) were injected into the internal carotid artery, permanently occluding the middle cerebral and/or anterior cerebral arteries. Rabbits were randomly assigned to treatment groups and sacrifice times as in Table 1. In all treated groups, intravenous DDFPe dosing with a 2% w/v emulsion began at 1 hour post-embolization and was repeated every 90 minutes until sacrifice at either 7 or 24 hours post-embolization. Following sacrifice, infarcts were measured as a percent of brain volume using vital stains on brain sections. Results: Percent infarct volume means significantly decreased for all DDFPe treated groups compared with controls (Table 1). Conclusion: Intravenous DDFPe begun 1 hour after stroke onset protects the brain from ischemic injury in the rabbit model of permanent embolic stroke. Decreased infarct volumes represent salvaged brain tissue. This effect can be observed for 24 hours with repeated doses.

Cerebral oxygen delivery by liposome-encapsulated hemoglobin: a positron-emission tomographic evaluation in a rat model of hemorrhagic shock

2007 ◽  
Vol 103 (1) ◽  
pp. 28-38 ◽  
Author(s):  
Vibhudutta Awasthi ◽  
Seong-Hwan Yee ◽  
Paul Jerabek ◽  
Beth Goins ◽  
William T. Phillips
Keyword(s):  
Human Serum Albumin ◽  
Serum Albumin ◽  
Human Serum ◽  
Rat Model ◽  
Oxygen Delivery ◽  
Oxygen Metabolism ◽  
Blood Substitutes ◽  
Oxygen Carriers ◽  
Positron Emission Tomographic ◽  
Positron Emission

Liposome-encapsulated Hb (LEH) is being developed as an artificially assembled, low-toxicity, and spatially isolated Hb-based oxygen carrier (HBOC). Standard methods of evaluating oxygen carriers are based on surrogate indicators of physiology in animal models of shock. Assessment of actual delivery of oxygen by HBOCs and resultant improvement in oxygen metabolism at the tissue level has been a technical challenge. In this work, we report our findings from 15O-positron emission tomographic (15O-PET) evaluation of LEH in a rat model of 40% hypovolemic shock. In vitro studies showed that PEGylated LEH formulation containing ∼7.5% Hb and consisting of neutral lipids (distearoylphosphatidylcholine:cholesterol:α-tocopherol, 51.4:46.4:2.2) efficiently picks up 15O-labeled oxygen gas. The final preparation of LEH contained 5% human serum albumin to provide oncotic pressure. Cerebral PET images of anesthetized rats inhaling 15O-labeled O2 gas showed efficient oxygen-carrying and delivery capacity of LEH formulation. From the PET images, we determined cerebral metabolic rate of oxygen (CMRO2) as a direct indicator of oxygen-carrying capacity of LEH as well as oxygen delivery and metabolism in rat brain. Compared with control fluids [saline and 5% human serum albumin (HSA)], LEH significantly improved CMR[Formula: see text] to ∼80% of baseline level. Saline and HSA resuscitation could not improve hypovolemia-induced decrease in CMR[Formula: see text]. On the other hand, resuscitation of shed blood was the most efficient in restoring oxygen metabolism. The results suggest that 15O-PET technology can be successfully employed to evaluate potential oxygen carriers and blood substitutes and that LEH resuscitation in hemorrhage enhances oxygen delivery to the cerebral tissue and improves oxygen metabolism in brain.

scholarly journals Characteristics of oxygen carriers in modern blood substitutes

2012 ◽  
Vol 93 (2) ◽  
pp. 398-400
Author(s):  
N V Shevchenko ◽  
S N Khudyakov ◽  
A A Zyryanov ◽  
D A Pyrenkov
Keyword(s):  
Oxygen Delivery ◽  
Blood Substitutes ◽  
Oxygen Carriers ◽  
Transport Function ◽  
Immune Disorders ◽  
Donor Blood ◽  
Pharmacological Agents ◽  
Artificial Oxygen Carriers ◽  
Long Time ◽  
Current Stage

Intraoperative and posttraumatic blood loss can be compensated by the introduction of crystalloid and colloid solutions. Blood transfusion is an effective method, but has several disadvantages: it may cause severe hemolytic reactions, infections and immune disorders. Blood substitutes based on oxygen-carrying molecules can solve most of these problems. The search for alternatives to donor blood and its preparations has continued for a long time, but only at this stage a few of the oxygen carriers have reached the phase of clinical trials. Artificial oxygen carriers are pharmacological agents used to improve oxygen delivery, regardless of the functions of erythrocytes, which perform solely a transport function of oxygen delivery. In this article, the authors have tried to reflect the current stage in the development, implementation and usage of oxygen carriers.

scholarly journals Polymerized bovine hemoglobin decreases oxygen delivery during normoxia and acute hypoxia in the rat

2008 ◽  
Vol 295 (3) ◽  
pp. H1090-H1099 ◽  
Author(s):  
David C. Irwin ◽  
Ben Foreman ◽  
Ken Morris ◽  
Molly White ◽  
Tim Sullivan ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Blood Loss ◽  
Oxygen Content ◽  
Oxygen Delivery ◽  
Acute Hypoxia ◽  
Bovine Hemoglobin ◽  
Oxygen Carriers ◽  
Nitric Oxide Synthase Inhibitor ◽  
Synthase Inhibitor ◽  
Oxide Synthase

Hemoglobin-based oxygen carriers (HBOC) have been primarily studied for blood loss treatment. More recently infusions of HBOC in euvolemic subjects have been proposed for a wide variety of potential therapies in which increased tissue oxygenation would be beneficial. However, compared with the exchange transfusion models to study blood loss, less is known about HBOC oxygen delivery and vasoacitvity when it is infused in euvolemic subjects. We hypothesized that HBOC [polymerized bovine hemoglobin (PBvHb)] infusion creating hypervolemia would increase oxygen delivery to tissues during acute global hypoxia. Vascular oxygen content and hemodynamics were determined after euvolemic rats were infused with 3 ml of either lactated Ringer or PBvHb solution (13 g/dl, 1.3 g/kg) during acute hypoxia (FIO2 = 10%, 4 h) or normoxia (FIO2 = 21%) exposure. Our data demonstrated that compared with Ringer-infused animals, in hypoxia and normoxia, PBvHb treatment improved oxygen content but raised mean arterial pressure, lowered stroke volume, heart rate, and cardiac index, which resulted in a net reduction in blood flow and oxygen delivery to the tissues. The PBvHb vasoactive effect was similar in magnitude and direction as to the Ringer-infused animals treated with a nitric oxide synthase inhibitor nitro-l-arginine, suggesting the PBvHb effect is mediated via nitric oxide scavenging. We conclude that infusion of PBvHb is not likely to be useful in treating global hypoxia under these conditions.

scholarly journals Urinary and anal incontinence among female gymnasts and cheerleaders—bother and associated factors. A cross-sectional study

2021 ◽  
Author(s):  
Kristina Lindquist Skaug ◽  
Marie Ellström Engh ◽  
Helena Frawley ◽  
Kari Bø
Keyword(s):  
Pelvic Floor ◽  
Anal Incontinence ◽  
Female Athletes ◽  
Cross Sectional Study ◽  
Sport Performance ◽  
Sports Performance ◽  
International Consensus ◽  
Cross Sectional ◽  
Negative Effect ◽  
Female Gymnasts

Abstract Introduction and hypothesis Artistic gymnastics, team gymnastics and cheerleading are sports including high-impact activities. It is presumed that the athletes’ pelvic floor must be functioning well to prevent urinary (UI) and anal incontinence (AI) during sports. The aim of this study was to investigate the prevalence and risk factors for UI and AI in female artistic gymnasts, team gymnasts and cheerleaders; the influence of UI and AI on daily living and sport performance; and the athletes’ knowledge about the pelvic floor muscles (PFM). Methods All female athletes ≥ 12 years of age competing in ≥ 1 National Championship in artistic gymnastics, team gymnastics or cheerleading in 2018/2019 were invited. International Consensus on Incontinence Questionnaires were used to assess the prevalence/bother of UI and AI. Results Among the 319 gymnasts and cheerleaders who participated, the prevalence of UI and AI was 67% and 84%, respectively. Age, training ≥ 4 days/week and straining to void were significantly associated with stress urinary incontinence (SUI) and years of training with AI. Eighty-three percent of athletes with SUI reported a negative effect on sports performance, 22% would occasionally avoid training or specific exercises because of leakage, and 28% used pads for protection. Forty-one percent of the athletes had never heard about the PFM, and 74% reported an interest in PFM training to prevent/treat UI or AI. Conclusions UI and AI were prevalent in female gymnasts and cheerleaders, and SUI negatively influenced sport performance. The athletes’ knowledge about the PFM was limited.

The spirit of sport, morality, and hypoxic tents: logic and authenticity

2007 ◽  
Vol 32 (2) ◽  
pp. 289-296 ◽  
Author(s):  
David Cruise Malloy ◽  
Robert Kell ◽  
Rod Kelln
Keyword(s):  
Athletic Training ◽  
Athletic Performance ◽  
Aerobic Performance ◽  
Altitude Training ◽  
Blood Doping ◽  
Hypoxic Environment ◽  
Moral Behaviour ◽  
World Anti Doping Agency ◽  
Future Policy ◽  
Spirit Of Sport

The World Anti-Doping Agency (WADA) has recently made a decision to allow the use of hypoxic tents amid a significant amount of controversy over the morality of their use for athletic training purposes. Currently, altitude training is considered moral, but other means of improving aerobic performance are not; for example, blood doping. Altitude training and blood doping have similar results, but the methods by which the results are achieved differ greatly. The controversy lies in how the use of a hypoxic device falls within WADA’s philosophy, which will then dictate future policy. This paper discusses the influence of a hypoxic environment on human physiology, altitude training’s influence on athletic performance, the concept of authentic physiology, and moral behaviour that is the foundation for logical debate.

Effect of two methods of hand heating on body temperature, forearm blood flow, and deep venous oxygen saturation

1990 ◽  
Vol 259 (5) ◽  
pp. E639-E643 ◽  
Author(s):  
I. W. Gallen ◽  
I. A. Macdonald
Keyword(s):  
Blood Flow ◽  
Body Temperature ◽  
Oxygen Content ◽  
Forearm Blood Flow ◽  
Venous Blood ◽  
Blood Oxygen ◽  
Left Hand ◽  
Venous Oxygen Saturation ◽  
Baseline Values ◽  
Healthy Females

Two methods of hand heating [warmed blanket 40 degrees C (WB) and warm-air box 55 degrees C (WA)] were compared with the effect of no heating (control) in six healthy females. After 30 min baseline, the left hand was either heated for 1 h or not heated. Measurements were made of skin temperature (ST), core temperature (CT), right forearm (FBF) and skin blood flow (SBF), and right forearm deep venous blood oxygen content with and without occlusion of the hand circulation. CT rose above baseline in WB (by +0.2 degrees C, P less than 0.01) but not with control or WA. Abdominal ST rose only with WB (by +0.66 degrees C above baseline, P less than 0.01). FBF increased above baseline values with both WA (by +10 ml.l forearm-1.min-1) and WB (by +12 ml.l forearm-1.min-1), but neither was significantly greater than the control. SBF increased above baseline only with WB (by +202 mV, P less than 0.01), and this was significantly greater than control SBF. With an occluded hand circulation, deep venous oxygen content rose above baseline values with WB only (+6.0%, P less than 0.01) but was not greater than control with either method of hand heating. We conclude that using a warm-air box has less effect than a heated blanket on the measured variables.

scholarly journals Automatic Oxygen Delivery System for Premature Babies

2010 ◽  
Vol 4 (2) ◽  
Author(s):  
Thao P. Do ◽  
Lindsey J. Eubank ◽  
Devin S. Coulter ◽  
John M. Freihaut ◽  
Carlos E. Guevara ◽  
...  
Keyword(s):  
Oxygen Saturation ◽  
Oxygen Concentration ◽  
Delivery System ◽  
Pulse Oximeter ◽  
Oxygen Delivery ◽  
Supplemental Oxygen ◽  
Saturation Level ◽  
Blood Oxygen ◽  
Blood Oxygen Saturation ◽  
Oxygen Saturation Level

When an infant is born prematurely, there are a number of health risks. Among these are underdeveloped lungs, which can lead to abnormal gas exchange of oxygen or hypoxemia. Hypoxemia is treated through oxygen therapy, which involves the delivery of supplemental oxygen to the patient but there are risks associated with this method. Risks include retinopathy, which can cause eye damage when oxygen concentration is too high, and brain damage, when the concentration is too low [1]. Supplemental oxygen concentration must be controlled rigorously. Currently healthcare staff monitors infants’ blood oxygen saturation level using a pulse oximeter. They manually adjust the oxygen concentration using an air-oxygen blender. Inconsistent manual adjustments can produce excessive fluctuations and cause the actual oxygen saturation level to deviate from the target value. Precision and accuracy are compromised. This project develops an automatic oxygen delivery system that regulates the supplemental oxygen concentration to obtain a target blood oxygen saturation level. A microprocessor uses a LABVIEW® program to analyze pulse oximeter and analyzer readings and control electronic valves in a redesigned air-oxygen blender. A user panel receives a target saturation level, displays patient data, and signals alarms when necessary. The prototype construction and testing began February 2010.

Blood flow, blood oxygen tension, oxygen uptake, and oxygen transport in skeletal muscle

1964 ◽  
Vol 206 (4) ◽  
pp. 858-866 ◽  
Author(s):  
Wendell N. Stainsby ◽  
Arthur B. Otis
Keyword(s):  
Blood Flow ◽  
Oxygen Uptake ◽  
Oxygen Tension ◽  
Capillary Density ◽  
Muscle Group ◽  
Blood Oxygen ◽  
Histological Techniques ◽  
Contracting Muscle ◽  
Resting Muscle

The effect of changes in blood flow and of blood oxygen tension on oxygen uptake of the in situ gastrocnemius-plantaris muscle group of the dog was examined. Oxygen uptake by resting muscle was not altered by changes in blood flow or blood oxygen tension except when these parameters were reduced below critical values. When the muscle group was contracting once per second, changes in blood oxygen tension were similarly without effect until a critically low value was reached. Although the contracting muscle used eight times as much oxygen per minute as resting muscle, the critical oxygen tension was lower than that for resting muscle. In an attempt to explain this observation the blood-tissue oxygen tension difference was estimated and used in the Krogh equation to calculate capillary density. The capillary density in contracting muscle was found to be much greater than in resting muscle and was about the same as the capillary density measured by others by histological techniques.

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