运动中的红细胞 运动和训练对红细胞供氧的影响Red blood cells in sports: effects of exercise and training on oxygen supply by red blood cells
德国海德堡海德尔堡大学运动医学诊所
在运动过程中，心血管系统必须保证工作肌肉的营养供应。在运动过程中，红细胞的主要功能是将氧气从肺部输送到组织，并将代谢产生的二氧化碳输送到肺部，以 便呼出。血红蛋白还有助于血液的缓冲能力，ATP和红细胞一氧化氮（NO）的释放有助于血管扩张和改善肌肉的血液流动。这些功能需要足够数量的红细胞在循环中。训练有素的运动员，尤其是耐力运动运动员，红细胞比积减少，有时被称为“运动性贫血”。“从临床意义上讲，这并不是贫血，因为与久坐不动的人相比，运动员血液中红细胞和血红蛋白的总量实际上增加了。”由训练引起的血细胞 比积的轻微下降是由血浆容积(PV)的增加引起的。通过训练增加红细胞总量的机制还不完全清楚。尽管刺激红细胞生成,运动可以降低红细胞数量，主要是通过血管内溶 解衰老红细胞,这是由于当红细胞通过收缩肌肉的毛细血管时，如跑步是足底或举重运动员的手掌产生的机械破裂。
总之，这些调整导致训练有素的运动员体内循环红细胞的平均年龄下降。这些年轻的红细胞的特征是氧的释放和变形能力得到改善，这两种都能改善运动过程中的组织氧供应。
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参考文献：
Red blood cells in sports: effects of exercise and training on oxygen supply by red blood cells
Front. Physiol., 12 November 2013 | https://doi.org/10.3389/fphys.2013.00332 Heimo Mairbäurl* Medical Clinic VII, Sports Medicine, University of Heidelberg, Heidelberg, Germany
During exercise the cardiovascular system has to warrant substrate supply to working muscle. The main function of red blood cells in exercise is the transport of O2 from the lungs to the tissues and the delivery of metabolically produced CO2 to the lungs for expiration. Hemoglobin also contributes to the blood's buffering capacity, and ATP and NO release from red blood cells contributes to vasodilation and improved blood flow to working muscle. These functions require adequate amounts of red blood cells in circulation. Trained athletes, particularly in endurance sports, have a decreased hematocrit, which is sometimes called “sports anemia.” This is not anemia in a clinical sense, because athletes have in fact an increased total mass of red blood cells and hemoglobin in circulation relative to sedentary individuals. The slight decrease in hematocrit by training is brought about by an increased plasma volume (PV). The mechanisms that increase total red blood cell mass by training are not understood fully. Despite stimulated erythropoiesis, exercise can decrease the red blood cell mass by intravascular hemolysis mainly of senescent red blood cells, which is caused by mechanical rupture when red blood cells pass through capillaries in contracting muscles, and by compression of red cells e.g., in foot soles during running or in hand palms in weightlifters. Together, these adjustments cause a decrease in the average age of the population of circulating red blood cells in trained athletes. These younger red cells are characterized by improved oxygen release and deformability, both of which also improve tissue oxygen supply during exercise. Introduction The primary role of red blood cells is the transport of respiratory gasses. In the lung, oxygen (O2) diffuses across the alveolar barrier from inspired air into blood, where the majority is bound by hemoglobin (Hb) to form oxy-Hb, a process called oxygenation. Hb is contained in the red blood cells, which, being circulated by the cardiovascular system, deliver O2 to the periphery where it is released from its Hb-bond (deoxygenation) and diffuses into the cells. While passing peripheral capillaries, carbon dioxide (CO2) produced by the cells reaches the red blood cells, where carbonic anhydrase (CA) in tissues and red blood cells converts a large portion of CO2 into bicarbonate (HCO−3). CO2 is also bound by Hb, preferentially by deoxygenated Hb forming carboxy-bonds. Both forms of CO2 are delivered to the lung, where CA converts HCO−3 back into CO2. CO2 is also released from its bond to Hb and diffuses across the alveolar wall to be expired. The biological significance of O2 transport by Hb is well-illustrated by anemia where decreased Hb also decreases exercise performance despite a compensatory increase in cardiac output (Ledingham, 1977; Carroll, 2007), and by improved aerobic performance upon increasing total Hb (Berglund and Hemmingson, 1987). The O2 dissociation curves in Figure 1 indicate the advantage of normal vs. anemic Hb showing that the O2 content in blood varies with the Hb concentration in blood at any given O2 partial pressure (PO2). Not only its amount but also the functional properties of Hb affect performance. This is illustrated by the observation that an increased Hb-O2 affinity favors O2 loading in the lung and survival in an hypoxic environment (Eaton et al., 1974; Hebbel et al., 1978), whereas a decreased Hb-O2 affinity favors the release of O2 from the Hb molecule in support of oxidative phosphorylation when the ATP demand is high, such as in exercising skeletal muscle (for a recent review see Mairbäurl and Weber, 2012).
https://www.frontiersin.org/articles/10.3389/fphys.2013.00332/full
