ACUTE INHALATION OF OZONE STIMULATES BRONCHIAL C-FIBERS AND RAPIDLY ADAPTING RECEPTORS IN DOGS
ACUTE INHALATION OF OZONE STIMULATES BRONCHIAL C-FIBERS AND RAPIDLY ADAPTING RECEPTORS IN DOGS
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DOI：
10.1152/jappl.1993.74.5.2345
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发表时间：
1993-05-01
影响因子：
3.3
通讯作者：
GREEN, JF
中科院分区：
文献类型：
--
作者：
COLERIDGE, JCG;COLERIDGE, HM;GREEN, JF
为了确定急性臭氧暴露引起迷走神经介导的呼吸变化的传入神经，我们记录了麻醉，开胸，人工通气犬的迷走神经冲动，并检查了肺对臭氧的传入反应（空气中2-3 ppm）输送到下气管20-60分钟。支气管C纤维（BrCs）是最容易受到臭氧影响的肺传入纤维，在臭氧暴露的1-7分钟内，11个BrCs中的10个的活性从0.2 +/- 0.2增加到4.6 +/- 1.3脉冲/秒。15个快速适应受体（RAR）中有10个被臭氧刺激，它们的活性从1.5 +/- 0.4增加到4.7 +/- 0.7脉冲/秒。刺激RAR（但不是BrCs）似乎继发于臭氧诱导的肺顺应性降低，因为它被肺的过度充气所消除。臭氧对肺C纤维或慢适应肺牵张受体的影响不大。我们的研究结果表明，BrCs和RAR都有助于急性暴露于臭氧引起的呼吸急促和支气管收缩，当迷走神经传导完整时，BrCs单独负责迷走神经介导的呼吸急促，其在迷走神经冷却至7 ℃时存活。
To identify the afferents responsible for initiating the vagally mediated respiratory changes evoked by acute exposure to ozone, we recorded vagal impulses in anesthetized, open-chest, artificially ventilated dogs and examined the pulmonary afferent response to ozone (2-3 ppm in air) delivered to the lower trachea for 20-60 min. Bronchial C-fibers (BrCs) were the lung afferents most susceptible to ozone, the activity of 10 of 11 BrCs increasing from 0.2 +/- 0.2 to 4.6 +/- 1.3 impulses/s within 1-7 min of ozone exposure. Ten of 15 rapidly adapting receptors (RARs) were stimulated by ozone, their activity increasing from 1.5 +/- 0.4 to 4.7 +/- 0.7 impulses/s. Stimulation of RARs (but not of BrCs) appeared secondary to the ozone-induced reduction of lung compliance because it was abolished by hyperinflation of the lungs. Ozone had little effect on pulmonary C-fibers or slowly adapting pulmonary stretch receptors. Our results suggest that both BrCs and RARs contribute to the tachypnea and bronchoconstriction evoked by acute exposure to ozone when vagal conduction is intact and that BrCs alone are responsible for the vagally mediated tachypnea that survives vagal cooling to 7-degrees-C.