A reevaluation of the validity of unrestrained plethysmography in mice
A reevaluation of the validity of unrestrained plethysmography in mice
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DOI：
10.1152/japplphysiol.00080.2002
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发表时间：
2002-10-01
影响因子：
3.3
通讯作者：
Bates, JHT
中科院分区：
文献类型：
--
作者：
Lundblad, LKA;Irvin, CG;Bates, JHT
目前，无限制的体积描记法被广泛用于评估小鼠的支气管反应性。从体积描记箱压[P-b（t），其中t是时间]推导出称为增强间歇的经验量，并假设其为支气管收缩的指数。我们表明，P-b（t）主要是由气体调节时，正常小鼠自发呼吸内的封闭室中的空气是在环境条件下。当室内的空气被加热和加湿到身体条件时，P-b（t）的变化减少了约三分之二。因此，其余的变化是由于肺内的气体压缩和膨胀，并且当动物通过增加的阻力呼吸时被放大。我们发现，吸气时的P-b（t）的时间积分可以通过一个包含气道阻力、功能残气量和潮气量的项来准确预测。我们的结论是，无限制的体积描记法可以用来准确地表征气道阻力的变化，只有功能性残气量和潮气量进行独立测量，并室气体是预处理的体温和湿度。
Presently, unrestrained plethysmography is widely used to assess bronchial responsiveness in mice. An empirical quantity known as enhanced pause is derived from the plethysmographic box pressure [P-b( t), where t is time] and assumed to be an index of bronchoconstriction. We show that P-b(t) is determined largely by gas conditioning when normal mice breathe spontaneously inside a closed chamber in which the air is at ambient conditions. When the air in the chamber is heated and humidified to body conditions, the changes in P-b(t) are reduced by about two-thirds. The remaining changes are thus due to gas compression and expansion within the lung and are amplified when the animals breathe through increased resistances. We show that the time integral of P-b(t) over inspiration is accurately predicted by a term containing airway resistance, functional residual capacity, and tidal volume. We conclude that unrestrained plethysmography can be used to accurately characterize changes in airway resistance only if functional residual capacity and tidal volume are measured independently and the chamber gas is preconditioned to body temperature and humidity.