Decline in peripheral chemoreceptor excitatory stimulation during acute hypoxia in the lamb.
Decline in peripheral chemoreceptor excitatory stimulation during acute hypoxia in the lamb.
复制标题
羔羊急性缺氧期间外周化学感受器兴奋性刺激下降。
DOI：
10.1152/jappl.1987.63.2.795
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发表时间：
1987
影响因子：
3.3
通讯作者：
M. Bureau
中科院分区：
文献类型：
--
作者：
J. Carroll;M. Bureau
在8只2- 3日龄未麻醉羔羊中研究了化学感受器功能，以连续评估缺氧化学感受器反射强度，在18分钟暴露于缺氧期间[吸入O2分数（FIO 2）= 0.08]。在缺氧过程中，在3，7和15分钟时测量了5次纯氧呼吸的即时呼吸（VE）下降。每只羔羊在10-11日龄时再次研究。在2-3日龄时，随着缺氧的开始，VE从658 +/- 133（SD）ml.min-1 X kg-1增加到1，124 +/- 177 ml.min-1 X kg-1的峰值。随后，VE反应出现减弱，在18分钟缺氧期间，VE平均下降319 ml.min-1 X kg-1。每次纯O2试验（Dejours试验）均导致VE突然下降（delta VEDejours）。在缺氧3、7和15分钟时，VE下降分别为937 +/- 163、868 +/- 244和707 +/- 120 ml.min-1 X kg-1。比较三个O2测试，三角洲VEDejours显着降低了15分钟，表明在缺氧期间的O2化学反射驱动的约四分之一的损失。在10-11日龄的测试显示，在缺氧期间，VE下降幅度较小。缺氧期开始和结束时的O2测试没有显着差异，这表明在更成熟的动物中缺氧化学反射驱动的损失较小。（250字处删节）
Chemoreceptor function was studied in eight 2- to 3-day-old unanesthetized lambs to sequentially assess hypoxic chemoreflex strength during an 18-min exposure to hypoxia [inspired O2 fraction (FIO2) = 0.08]. The immediate ventilatory (VE) drop in response to five breaths of pure O2 was measured at 3, 7, and 15 min during hypoxia. Each lamb was studied again at 10-11 days of age. At 2-3 days of age VE increased, with the onset of hypoxia, from 658 +/- 133 (SD) ml.min-1 X kg-1 to a peak of 1,124 +/- 177 ml.min-1 X kg-1. A dampening of the VE response then occurred, with a mean decline in VE of 319 ml.min-1 X kg-1 over the 18-min hypoxia period. Each pure O2 test (Dejours test) resulted in an abrupt fall in VE (delta VEDejours). This VE drop was 937 +/- 163, 868 +/- 244, and 707 +/- 120 ml.min-1 X kg-1 at 3, 7, and 15 min of hypoxia, respectively. Comparing the three O2 tests, delta VEDejours was significantly decreased by 15 min, indicating a loss of about one-fourth of the O2 chemoreflex drive during hypoxia. Testing at 10-11 days of age revealed a smaller VE decline during hypoxia. O2 tests at the beginning and end of the hypoxic period were not significantly different, indicating a smaller loss of hypoxic chemoreflex drive in the more mature animals.(ABSTRACT TRUNCATED AT 250 WORDS)