Institute of Environmental Sciences, Jagiellonian University, Gronostajowa 7, 30-387, Krakow, Poland
Institute of Environmental Sciences, Jagiellonian University, Gronostajowa 7, 30-387, Krakow, Poland.
J Exp Biol. 2019 Feb 18;222(Pt 4):jeb193227. doi: 10.1242/jeb.193227.
Physical aerobic activity is oxygen demanding, but - particularly for birds - there is still little understanding of how blood contributes to oxygen supply under various activity levels. In a two-factorial experimental design, we investigated the long-term effect of daily flight training and the immediate effect of a short exercise bout on a set of haematological variables: haemoglobin (Hb) content, haematocrit (Hct), and red blood cell number (RBC) and size (RBC) in zebra finches (). For a period of 6 weeks, birds were either trained daily for 3 h in a flight arena or remained untrained. Subsequently, half of each group was blood sampled either in the resting condition or after a 5 min exercise bout in a flight-hover wheel. We found significantly lower Hb content, Hct and RBC compared with that in untrained controls in response to training, while RBC did not differ between treatments. Response to an exercise bout revealed the opposite pattern, with significantly higher Hb content and Hct compared with that in non-exercised birds. Additionally, RBC was significantly smaller immediately after exercise compared with that in non-exercised birds, and such short-term flexibility represents a novel finding for birds. This contrasting response in erythrocyte characteristics with respect to long-term training and short exercise bouts appears as a clear pattern, presumably underlain by changes in water balance. We infer alterations of blood flow to be involved in adequate oxygen supply. During an exercise bout, RBC flexibility may not only enhance oxygen delivery through improved erythrocyte surface area to volume ratio but also improve blood flow through a compensatory effect on blood viscosity.
身体有氧运动是需要氧气的，但 - 特别是对于鸟类 - 对于血液在各种活动水平下如何提供氧气仍然知之甚少。在双因素实验设计中，我们研究了日常飞行训练的长期影响和短暂运动对一组血液变量的即时影响：血红蛋白 (Hb) 含量、血细胞比容 (Hct) 和红细胞数量 (RBC) 和大小 (RBC) 在斑胸草雀 (). 在 6 周的时间里，鸟类要么每天在飞行竞技场训练 3 小时，要么保持不训练。随后，每组的一半在休息状态或在飞行-悬停轮中进行 5 分钟运动后进行采血。我们发现，与未经训练的对照组相比，训练导致 Hb 含量、Hct 和 RBC 显著降低，而 RBC 在处理之间没有差异。对运动的反应呈现出相反的模式，Hb 含量和 Hct 明显高于未运动的鸟类。此外，与未运动的鸟类相比，RBC 在运动后立即变小，这种短期的灵活性是鸟类的一个新发现。红细胞特征对长期训练和短期运动的这种对比反应似乎是一个明显的模式，可能是水平衡变化的结果。我们推断，血液流动的改变参与了足够的氧气供应。在运动过程中，RBC 的灵活性不仅可以通过改善红细胞表面积与体积比来增强氧气输送，还可以通过对血液粘度的补偿作用来改善血液流动。
