Darquenne C, West J B, Prisk G K
Department of Medicine, University of California, San Diego, La Jolla, California 92093-0931, USA.
J Appl Physiol (1985). 1998 Oct;85(4):1252-9. doi: 10.1152/jappl.1998.85.4.1252.
We performed bolus inhalations of 1-micrometer particles in four subjects on the ground (1 G) and during parabolic flights both in microgravity (microG) and in approximately 1.6 G. Boluses of approximately 70 ml were inhaled at different points in an inspiration from residual volume to 1 liter above functional residual capacity. The volume of air inhaled after the bolus [the penetration volume (Vp)] ranged from 200 to 1,500 ml. Aerosol concentration and flow rate were continuously measured at the mouth. The deposition, dispersion, and position of the bolus in the expired gas were calculated from these data. For Vp >/=400 ml, both deposition and dispersion increased with Vp and were strongly gravity dependent, with the greatest deposition and dispersion occurring for the largest G level. At Vp = 800 ml, deposition and dispersion increased from 33.9% and 319 ml in microG to 56.9% and 573 ml at approximately 1.6 G, respectively (P < 0.05). At each G level, the bolus was expired at a smaller volume than Vp, and this volume became smaller with increasing Vp. Although dispersion was lower in microG than in 1 G and approximately 1.6 G, it still increased steadily with increasing Vp, showing that nongravitational ventilatory inhomogeneity is partly responsible for dispersion in the human lung.
我们在地面（1G）以及抛物线飞行期间，在微重力（microG）和大约1.6G的条件下，对四名受试者进行了1微米颗粒的单次吸入。单次吸入量约为70ml，在从残气量到功能残气量以上1升的吸气过程中的不同点进行吸入。单次吸入后吸入的空气量[穿透量（Vp）]在200至1500ml之间。在口腔处连续测量气溶胶浓度和流速。根据这些数据计算单次吸入物在呼出气体中的沉积、扩散和位置。对于Vp≥400ml，沉积和扩散均随Vp增加而增加，且强烈依赖于重力，在最大G水平下沉积和扩散最大。当Vp = 800ml时，沉积和扩散分别从微重力下的33.9%和319ml增加到大约1.6G时的56.9%和573ml（P < 0.05）。在每个G水平下，单次吸入物的呼出量均小于Vp，且该量随Vp增加而减小。尽管微重力下的扩散低于1G和大约1.6G时的扩散，但它仍随Vp增加而稳步增加，表明非重力通气不均匀性部分导致了人体肺部的扩散。
