Bronchodilatory effect of deep inspiration on the dynamics of bronchoconstriction in mice
Bronchodilatory effect of deep inspiration on the dynamics of bronchoconstriction in mice
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DOI：
10.1152/japplphysiol.00698.2007
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发表时间：
2007-11-01
影响因子：
3.3
通讯作者：
Lundblad, Lennart K. A.
中科院分区：
文献类型：
--
作者：
Bates, Jason H. T.;Cojocaru, Ana;Lundblad, Lennart K. A.
我们最近开发了一个气道嵌入弹性实质的计算模型（Bates JH, Lauzon AM）。[J] . journal of clinical nursing, 2008,(1): 1 - 2)，准确模拟正常动物注射甲胆碱后气道阻力对潮气量和呼气末正压（PEEP）的时间依赖性。在本研究中，我们比较了支气管激动剂甲胆碱给药后肺深度膨胀（DI）引起的支气管扩张模型预测与小鼠相应的实验测量结果。我们发现，在静脉注射甲胆碱后不久给药时，小鼠气道阻力立即降低，而气道平滑肌处于收缩过程中。然而，阻力减小的幅度比模型预测的要大，其随后的增加速率要小。我们发现，当在注射甲胆碱后大约3秒内给予DI时，这种效果最为明显，这再次与模型的预测相反。然而，气道阻力的降低实际上与肺充气率无关，这与模型预测一致。我们得出的结论是，虽然模型解释了实验中观察到的DI后气道阻力降低的很大一部分，但预测和实验之间仍然存在重要差异，这表明DI的影响不仅仅是由于气道平滑肌的偏心收缩。
We recently developed a computational model of an airway embedded in elastic parenchyma ( Bates JH, Lauzon AM. J Appl Physiol 102: 1912 - 1920, 2007) that accurately mimics the time dependence of airway resistance on tidal volume and positive end- expiratory pressure ( PEEP) following methacholine injection in normal animals. In the present study, we compared the model predictions of bronchodilation induced by a deep inflation ( DI) of the lung following administration of the bronchial agonist methacholine to corresponding experimental measurements made in mice. We found that a DI in mice caused an immediate reduction in airway resistance when it was administered soon after intravenous injection of methacholine, while the airway smooth muscle was in the process of contracting. However, the magnitude of the reduction in resistance was greater and its subsequent rate of increase less than that predicted by the model. We found that this effect was most pronounced when the DI was given within similar to 3 s following methacholine injection, again in contrast to the predictions of the model. The reduction of airway resistance was virtually independent of the rate of lung inflation during the DI, however, which agrees with model predictions. We conclude that while the model accounts for a substantial fraction of the post- DI reduction in airway resistance seen experimentally, there remain important differences between prediction and experiment that suggest that the effects of a DI are not simply due to eccentric contraction of the airway smooth muscle.