Ivy Catherine M, York Julia M, Lague Sabine L, Chua Beverly A, Alza Luis, McCracken Kevin G, Milsom William K, Scott Graham R
Physiol Biochem Zool. 2018 May/Jun;91(3):859-867. doi: 10.1086/697053.
Hypoxia at high altitudes constrains O supply to support metabolism, thermoregulation in the cold, and exercise. High-altitude natives that somehow overcome this challenge-who live, reproduce, and sometimes perform impressive feats of exercise at high altitudes-are a powerful group in which to study the evolution of physiological systems underlying hypoxia resistance. Here, we sought to determine whether a common pulse oximetry system for rodents (MouseOx Plus) can be used reliably in studies of high-altitude birds by examining the hypoxia responses of the Andean goose. We compared concurrent measurements of heart rate obtained using pulse oximetry versus electrocardiography. We also compared our measurements of peripheral arterial O saturation (SaO) in uncannulated birds with published data collected from blood samples in birds that were surgically implanted arterial cannulae. Responses to acute hypoxia were measured during stepwise reductions in inspired partial pressure of O. Andean geese exhibited very modest breathing and heart rate responses to hypoxia but were nevertheless able to maintain normal O consumption rates during severe hypoxia exposure down to 5 kPa O. There were some minor quantitative differences between uncannulated and cannulated birds, which suggest that surgery, cannulation, and/or other sources of variability between studies had modest effects on the hypoxic ventilatory response, heart rate, blood hemoglobin, and hematocrit. Nevertheless, measurements of heart rate and SaO by pulse oximetry had small standard errors and were generally concordant and well correlated with measurements using other techniques. We conclude that the MouseOx Plus pulse oximetry system can be a valuable tool for studying the cardiorespiratory physiology of waterfowl without the deleterious effects of surgery/cannulation.
高海拔地区的缺氧状况限制了氧气供应，从而影响新陈代谢、寒冷环境下的体温调节以及运动。一些高海拔地区的原住民能够克服这一挑战——他们在高海拔地区生活、繁衍，有时还能完成令人惊叹的运动壮举——这是研究抗缺氧生理系统进化的有力群体。在此，我们试图通过研究安第斯鹅的缺氧反应，来确定一种用于啮齿动物的通用脉搏血氧仪系统（MouseOx Plus）是否能可靠地用于高海拔鸟类的研究。我们比较了使用脉搏血氧仪与心电图同时测量的心率。我们还将未插管鸟类的外周动脉血氧饱和度（SaO）测量值与已发表的、从手术植入动脉插管的鸟类血液样本中收集的数据进行了比较。在逐步降低吸入氧气分压的过程中测量对急性缺氧的反应。安第斯鹅对缺氧的呼吸和心率反应非常轻微，但在低至5 kPa氧气的严重缺氧暴露期间仍能维持正常的氧气消耗率。未插管和插管鸟类之间存在一些微小的定量差异，这表明手术、插管和/或研究之间的其他变异性来源对缺氧通气反应、心率、血液血红蛋白和血细胞比容有适度影响。然而，通过脉搏血氧仪测量的心率和SaO的标准误差较小，并且通常与使用其他技术的测量结果一致且相关性良好。我们得出结论，MouseOx Plus脉搏血氧仪系统可以成为研究水禽心肺生理学的有价值工具，而不会产生手术/插管的有害影响。
