Anatomic localization of 24-and 96-h particle retention in canine airways
Anatomic localization of 24-and 96-h particle retention in canine airways
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DOI：
10.1152/jappl.1999.87.1.269
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发表时间：
1999-07-01
影响因子：
3.3
通讯作者：
Ziesenis, A
中科院分区：
文献类型：
--
作者：
Kreyling, WG;Blanchard, JD;Ziesenis, A
犬气道中24小时和96小时微粒滞留的解剖学定位。应用生理学杂志，87（1）：269-284，1999。长期滞留在气道中的颗粒是有争议的。然而，在人体中不可能对颗粒进行精确的解剖定位。在这项研究中，在麻醉、通气的比格犬中确定了浅团吸入后保留颗粒的解剖位置。将50个含有单分散2.5 μ m聚苯乙烯颗粒（PSL）的30 cm（3）大丸剂输送至81-129 cm（3）的浅肺深度。在安乐死前96 h，使用红色荧光PSL;在24 h，使用绿色荧光PSL和Tc-99 m标记的PSL。在接下来的24小时内测量Tc-99 m-PSL的清除率。在微波固定的肺组织的系统的、体积加权的随机样本中确定颗粒保留的位点。精确的颗粒定位和分布进行了分析，使用γ计数，传统的荧光显微镜，共聚焦显微镜。在浅推注吸入后24小时内，50-95%的沉积的Tc-99 m-PSL被清除，但剩余部分在所有犬中被缓慢清除，与先前的人体结果相似。三维沉积模式显示颗粒在隆突水平处横跨肺的整个横截面平面。在这些位置，33+/-9.9%的滞留颗粒存在于小的非呼吸道（直径0.3- 1 mm）中，49 +/-10%的颗粒存在于肺泡中;其余部分存在于较大的气道中。96小时后，发现类似的模式。这些结果表明，长期滞留在气道是在细支气管水平。
Anatomic localization of 24- and 96-h particle retention in canine airways. J. Appl. Physiol. 87(1): 269-284, 1999.-Long-term retention of particles in airways is controversial. However, precise anatomic localization of the particles is not possible in people. In this study the anatomic location of retained particles after shallow bolus inhalation was determined in anesthetized, ventilated beagle dogs. Fifty 30-cm(3) boluses containing monodisperse 2.5-mu m polystyrene particles (PSL) were delivered to a shallow lung depth of 81-129 cm(3). At 96 h before euthanasia, red fluorescent PSL were used; at 24 h, green fluorescent PSL and Tc-99m-labeled PSL were used. Clearance of Tc-99m-PSL was measured during the next 24 h. Sites of particle retention were determined in systematic, volume-weighted random samples of microwave-fixed lung tissue. Precise particle localization and distribution was analyzed by using gamma counting, conventional fluorescence microscopy, and confocal microscopy. Within 24 h after shallow bolus inhalation, 50-95% of the deposited Tc-99m-PSL were cleared, but the remaining fraction was cleared slowly in all dogs, similar to previous human results. The three-dimensional deposition patterns showed particles across the entire cross-sectional plane of the lungs at the level of the carina. In these locations, 33+/-9.9%; of the retained particles were found in small, nonrespiratory airways (0.3- to 1-mm diameter) and 49 +/- 10% of the particles in alveoli; the remaining fraction was found in larger airways. After 96 h, a similar pattern was found. These findings suggest that long-term retention in airways is at the bronchiolar level.