Effect of episodic hypoxia on sympathetic activity and blood pressure
Effect of episodic hypoxia on sympathetic activity and blood pressure
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DOI：
10.1016/s0034-5687(99)00114-0
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发表时间：
2000-02-01
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影响因子：
--
通讯作者：
Fletcher, EC
中科院分区：
文献类型：
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作者：
Fletcher, EC
阻塞性睡眠呼吸暂停(OSA)的主要表现之一是睡眠中严重的反复(间歇性)低氧。急性缺氧导致外周化学感受器的刺激，进而直接增加交感神经流出。交感神经流出的增加被认为是至少部分直接导致阻塞性睡眠呼吸暂停综合征的急性血压变化的原因。然而，研究反复间歇性低氧(EH)对人类的慢性影响是困难的，因为慢性心血管变化可能需要许多年才能显现。为此，我们开发了一种方法，为大鼠提供持续35天的反复短期低氧(类似于人类OSA的间歇性脱饱和)，刺激化学感受器和交感神经系统，从而检查EH的慢性心血管反应。大鼠EH的结果是，在停止每日EH后，静息(未刺激)平均血压升高10-14毫米汞柱，持续数周。颈动脉体部去神经、交感神经消融、肾交感神经切除、肾上腺髓质摘除和血管紧张素-L受体阻滞剂氯沙坦均可阻断血压升高。因此，肾上腺素能和肾素-血管紧张素系统过度活动似乎是EH早期慢性血压升高的原因，也可能是人类高血压合并OSA的原因。(C)2000 Elsevier Science B.V.保留所有权利。
One of the major manifestations of obstructive sleep apnea (OSA) is profound and repeated (episodic) hypoxia during sleep. Acute hypoxia leads to stimulation of the peripheral chemoreceptors, which in turn directly increase sympathetic outflow. It is believed that this increase in sympathetic outflow is directly responsible, at least in part, for the acute blood pressure (BP) changes seen in OSA. It is difficult however, to study the chronic effects of repeated episodic hypoxia (EH) in humans since the chronic cardiovascular changes may take many years to manifest. For this reason, we developed a method of providing recurrent short periods of hypoxia (resembling the episodic desaturation in humans with OSA) to rats for 35 days, stimulating the chemoreceptors and the sympathetic nervous system, allowing examination of the chronic cardiovascular response to EH. The result of EH in rats is a 10-14 mmHg increase in resting (unstimulated) mean BP that lasts for several weeks after cessation of the daily EH. This BP increase is blocked by carotid body denervation, sympathetic nerve ablation, renal sympathectomy, adrenal medullectomy, and the angiotensin-l receptor blocker losartan. Thus, it appears that adrenergic and renin-angiotensin system over-activity contribute to the early chronic elevated BP in EH and perhaps in human hypertension associated with OSA. (C) 2000 Elsevier Science B.V. All rights reserved.