The effect of gas exchange on multiple-breath nitrogen washout measures of ventilation inhomogeneity in the mouse.
The effect of gas exchange on multiple-breath nitrogen washout measures of ventilation inhomogeneity in the mouse.
复制标题
气体交换对小鼠通气不均匀性多次呼吸氮气冲刷措施的影响。
DOI：
10.1152/japplphysiol.00543.2014
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发表时间：
2014
期刊：
影响因子：
--
通讯作者：
Thompson,BruceR
中科院分区：
文献类型：
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作者：
Dharmakumara,Mahesh;Prisk,GKim;Royce,SimonG;Tawhai,Merryn;Thompson,BruceR
在小动物的肺中，使用氧气的惰性气体冲刷测量由于连续的氧气消耗过程(V̇O2)而变得复杂。多次呼吸氮气冲洗(MBNW)技术使用肺泡斜率来确定腺泡(Socin)和传导(Scond)气道区域的通风不均质性，以及由肺清除指数(LCI)确定的总体不均质性。我们假设，在小鼠活体肺中测量到的通风不均匀实际上是由于高V̇O2与肺泡气体容量(Va)成比例造成的伪影，而不是通风不均匀本身。在7只雄性C57BL/6小鼠中，分别在活体和死后进行MBNW，以得出在有和没有气体交换影响的情况下的措施。将这些结果与小鼠肺的非对称多支点数学模型的结果进行了比较。活体与死后结果比较差异无统计学意义(SacinAlive=0.311±0.043 ml−1，死后LCI=0.338±0.032 ml−1，LCI7.0±0.1)。−-1活着时为0.086±0.005毫升，死后为0.006±0.002毫升，较死前显著下降(P<0.01)。模型模拟重复了这些结果。此外，在模型中，随着V̇O2的增加，肺泡斜率也增加。这些发现表明，小鼠肺中Scons的MBNW测量受到气体交换的影响，这是这种小动物高V̇O2-to-Variatio的结果，而不是由于呼吸道内的不均匀。
Inert-gas washout measurements using oxygen, in the lungs of small animals, are complicated by the continuous process of oxygen consumption (V̇o2). The multiple-breath nitrogen washout (MBNW) technique uses the alveolar slope to determine measures of ventilation inhomogeneity in the acinar (Sacin) and conducting (Scond) airway regions, as well as overall inhomogeneity, as determined by the lung clearance index (LCI). We hypothesized that measured ventilation inhomogeneity in the mouse lung while it is alive is in fact an artifact due to the high V̇o2in proportion to alveolar gas volume (Va), and not ventilation inhomogeneity per se. In seven male C57BL/6 mice, MBNW was performed alive and postmortem to derive measures with and without the effect of gas exchange, respectively. These results were compared with those obtained from an asymmetric multibranch point mathematical model of the mouse lung. There was no statistical difference inSacinand LCI between alive and postmortem results (Sacinalive = 0.311 ± 0.043 ml−1andSacinpostmortem = 0.338 ± 0.032 ml−1, LCI alive = 7.0 ± 0.1 and LCI postmortem = 7.0 ± 0.1). However, there was a significant decrease inScondfrom 0.086 ± 0.005 ml−1alive to 0.006 ± 0.002 ml−1postmortem (P< 0.01). Model simulations replicated these results. Furthermore, in the model, as V̇o2increased, so did the alveolar slope. These findings suggests that the MBNW measurement ofScondin the mouse lung is confounded by the effect of gas exchange, a result of the high V̇o2-to-Varatio in this small animal, and not due to inhomogeneity within the airways.