Chronic hyperoxia alters the early and late phases of the hypoxic ventilatory response in neonatal rats
Chronic hyperoxia alters the early and late phases of the hypoxic ventilatory response in neonatal rats
复制标题
DOI：
10.1152/japplphysiol.00510.2010
复制
发表时间：
2010-09-01
影响因子：
3.3
通讯作者：
Rampersad, Donna A.
中科院分区：
文献类型：
--
作者：
Bavis, Ryan W.;Young, Kristen M.;Rampersad, Donna A.
Bavis RW、Young KM、Barry KJ、Boller MR、Kim E、Klein PM、Ovrutsky AR、Rampersad DA。慢性高氧改变了新生大鼠缺氧通气反应的早期和晚期。 J Appl Physiol 109: 796-803, 2010。首次发表于 2010 年 6 月 24 日； doi: 10.1152/japplphyol.00510.2010.-出生后 1-4 周内的慢性高氧会减弱随后在成年大鼠中测量的缺氧通气反应 (HVR)。本研究没有关注这种持久的可塑性，而是考虑了高氧对新生儿期呼吸控制的影响。 Sprague-Dawley 大鼠在 60% O(2) 中出生和饲养，直至在出生后年龄 (P) 4、6-7 或 13-14 天进行研究。分别使用头体体积描记法和呼吸测量法在常氧（21% O(2)）和急性缺氧（12% O(2)）下测量通气和代谢。与在室内空气中饲养的年龄匹配的大鼠相比，主要发现是1）P4和P6-7在常氧条件下肺通气和代谢O（2）消耗减少； 2) 含氧量正常时呼吸稳定性下降； 3) P6-7和P13-14处HVR早期阶段的衰减； 4) 在所研究的所有年龄段，缺氧期间通气量持续增加（相对于正常双相 HVR）。早期 HVR 的减弱可能反映了外周动脉化学感受器的进行性损伤，而 P7 之前新生儿中持续 HVR 的表达表明高氧也会诱导中枢神经系统内的可塑性。总之，这些结果表明高氧对发育中的呼吸控制系统的抑制和兴奋作用之间存在复杂的相互作用。
Bavis RW, Young KM, Barry KJ, Boller MR, Kim E, Klein PM, Ovrutsky AR, Rampersad DA. Chronic hyperoxia alters the early and late phases of the hypoxic ventilatory response in neonatal rats. J Appl Physiol 109: 796-803, 2010. First published June 24, 2010; doi: 10.1152/japplphysiol.00510.2010.-Chronic hyperoxia during the first 1-4 postnatal weeks attenuates the hypoxic ventilatory response (HVR) subsequently measured in adult rats. Rather than focusing on this long-lasting plasticity, the present study considered the influence of hyperoxia on respiratory control during the neonatal period. Sprague-Dawley rats were born and raised in 60% O(2) until studied at postnatal ages (P) of 4, 6-7, or 13-14 days. Ventilation and metabolism were measured in normoxia (21% O(2)) and acute hypoxia (12% O(2)) using head-body plethysmography and respirometry, respectively. Compared with age-matched rats raised in room air, the major findings were 1) diminished pulmonary ventilation and metabolic O(2) consumption in normoxia at P4 and P6-7; 2) decreased breathing stability during normoxia; 3) attenuation of the early phase of the HVR at P6-7 and P13-14; and 4) a sustained increase in ventilation during hypoxia (vs. the normal biphasic HVR) at all ages studied. Attenuation of the early HVR likely reflects progressive impairment of peripheral arterial chemoreceptors while expression of a sustained HVR in neonates before P7 suggests that hyperoxia also induces plasticity within the central nervous system. Together, these results suggest a complex interaction between inhibitory and excitatory effects of hyperoxia on the developing respiratory control system.