Adult carotid chemoafferent responses to hypoxia after 1, 2, and 4 wk of postnatal hyperoxia
Adult carotid chemoafferent responses to hypoxia after 1, 2, and 4 wk of postnatal hyperoxia
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DOI：
10.1152/japplphysiol.00985.2002
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发表时间：
2003-09-01
影响因子：
3.3
通讯作者：
Mitchell, GS
中科院分区：
文献类型：
--
作者：
Bisgard, GW;Olson, EB;Mitchell, GS
将新生大鼠暴露于出生后高氧（60%O-2）中1-4周，可减弱成年大鼠对急性缺氧的呼吸和膈神经反应。本研究的目的是增加我们的理解，颈动脉化学感受器传入神经输入在这种抑郁反应与不同持续时间的出生后高氧暴露。大鼠出生前几天暴露于60%O-2的1，2或4周，并在常氧条件下3-5个月后进行研究。用乌拉坦麻醉大鼠。整个颈动脉窦神经（CSN）的反应NaCN（40微克/公斤静脉注射），10秒的窒息和急性等二氧化碳缺氧（动脉PO 2 45托）进行了测定。与对照组相比，出生后高氧刺激的平均CSN反应降低。暴露于出生后高氧1周的大鼠的反应受到的影响小于暴露于2和4周的高氧，这是彼此相当。这些研究说明了在出生后的前2周内，正常氧含量对颈动脉化学感受器传入功能发育的重要性。
Exposing newborn rats to postnatal hyperoxia (60% O-2) for 1-4 wk attenuates the ventilatory and phrenic nerve responses to acute hypoxia in adult rats. The goal of this research was to increase our understanding of the carotid chemoreceptor afferent neural input in this depressed response with different durations of postnatal hyperoxic exposure. Rats were exposed from a few days before birth to 1, 2, or 4 wk of 60% O-2 and studied after 3-5 mo in normoxia. The rats were anesthetized with urethane. Whole carotid sinus nerve (CSN) responses to NaCN (40 mug/kg iv), 10 s of asphyxia and acute isocapnic hypoxia ( arterial PO2 45 Torr) were determined. Mean CSN responses to stimuli after postnatal hyperoxia were reduced compared with controls. Responses in rats exposed to 1 wk of postnatal hyperoxia were less affected than those exposed to 2 and 4 wk of hyperoxia, which were equivalent to each other. These studies illustrate the importance of normoxia during the first 2 wk of life in development of carotid chemoreceptor afferent function.