Article

Hemoglobin concentration and aerobic work capacity in women following induced erythrocythemia.

ABSTRACT The effect of induced erythrocythemia on hemoglobin concentration ([Hb]) and aerobic work capacity was determined for nine women. Cycle tests were performed at prereinfusion (T1), 2 days after a placebo infusion (T2), 2 days postreinfusion of 334 ml of red blood cells (T3), 8 days postreinfusion (T4), and 14 days postreinfusion (T5). T1 and T2 responses did not differ, negating a placebo effect. [Hb] increased from 12.7 g X dl at T1 to 14.7 g X dl at T3 and then remained constant at T4 and T5. Hematocrit increased from 38.1% at T1 to 44.9% at T3 and then remained constant at T4 and T5. Submaximal O2 uptake (VO2) and stroke volume (SV) did not change from T1 through T5. Submaximal cardiac output (Q) and heart rate (HR) decreased from T1 to T3 and then remained constant at T4 and T5. Arteriovenous O2 difference increased from T1 to T3 and then remained constant at T4 and T5. Maximal VO2 was greater at T3 (2.65 l X min-1), T4 (2.66 l X min-1), and T5 (2.60 l X min-1) than at T1 (2.41 l X min-1). Physical work capacity was greater at T3 (10,740 kg X m), T4 (10,980 kg X m), and T5 (10,380 kg X m) than at T1 (8,747 kg X m). Maximal values for Q, HR, and SV were unchanged from T1 through T5. At maximum, arteriovenous O2 difference and Hb flow rate increased from T1 to T3 and then remained constant at T4 and T5. The greater postreinfusion [Hb] improved O2 transport capacity and appeared to regulate circulatory responses.

0 Followers
 · 
55 Views
  • [Show abstract] [Hide abstract]
    ABSTRACT: Blood doping in sports has been a hot topic of present. Longitudinal follow up of hematological parameters in different endurance sports, during the 1990s and early 2000s, has provided considerable suspicions about extensive blood manipulation, with performance enhancing effects. Recent doping revelations in the media also prove that blood doping is not an anticipated myth but it is, in fact, real. Erythropoiesis stimulating agents and autologous blood transfusions are used in synergy with substantial effect on the maximum oxygen uptake and delivery to muscles. Whilst both methods of blood manipulation represent a potential health hazard, in the context of an elevated hematocrit, nevertheless despite a number of suspicious deaths amongst athletes, this has not yet been fully documented. A reliable test for detection of recombinant human erythropoietin was implemented in 2000, but this is probably circumvented by microdose regimens. The Athlete's Biological Passport represents the progeny of the idea of an indirect approach based on long term monitoring of hematological parameters, thus making it possible to detect autologous blood doping and erythropoietin use after the substance is excreted. Nevertheless with advances in anti-doping measures it is possible that the levels of excretion of substances used can be masked. Clearly more sensitive and specific diagnostic tools and research/development in these areas of major concern are warranted, which, combined with changes in the athlete's attitude, will help in reaching the vision of fair play.
    Transfusion and Apheresis Science 06/2013; 49(1). DOI:10.1016/j.transci.2013.05.014 · 1.07 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: When current antidoping programmes were developed, the most frequently used doping agents were xenobiotics, such as stimulants and anabolic steroids, that are readily detectable in urine with the use of gas chromatography and mass spectrometry. As control of traditional doping agents became effective, some athletes turned to other means to improve performance, including blood doping and the application of recombinant peptide hormones such as erythropoietin and growth hormone.Dopingwith these agents is not easily detected in urine samples, and therefore new strategies must be developed as a supplement to those already in use. Such strategies will probably include analysing blood samples, as several of the most promising methods that are able to detect modern doping agents use blood as the analytical matrix. Non-autologous blood doping results in an admixture of self and foreign red blood cells that can be detected in a blood sample with the methods available. Methods to indicate doping with erythropoietin include the indirect finding of an elevated level of soluble transferrin receptor in serum, or a direct demonstration of a shift from the normal to an abnormal spectrum of erythropoietin isoforms. To indicate doping with growth hormone, a set of serum parameters including insulin growth factors and their binding proteins are under investigation as indirect evidence. A direct method using isotopic differences between endogenous and recombinant growth hormones is being investigated. A similar method has been established to detect the administration of testosterone esters. Several legal and ethical questions must be solved before blood sampling can become a part of routine doping control, but themajor ethical question is whether sport can continue as today without proper methods to detect many modern doping agents.
    Sports Medicine 28(1). DOI:10.2165/00007256-199928010-00003 · 5.32 Impact Factor