Bernard S L, Glenny R W, Polissar N L, Luchtel D L, Lakshminarayan S
Division of Pulmonary and Critical Care Medicine, University of Washington, and Veterans Affairs Medical Center, Seattle 98195, USA.
J Appl Physiol (1985). 1996 Feb;80(2):430-6. doi: 10.1152/jappl.1996.80.2.430.
This study determined the relative contributions of systemic (bronchial) and pulmonary blood flow to the intraparenchymal airways >1 mm in diameter by using 15-mu m fluorescent microspheres and fluorescence microscopy in four dogs. Fluorescent microspheres of one color were injected into the inferior vena cava as a pulmonary blood flow marker, and fluorescent microspheres of another color were injected into the left ventricle as a systemic blood flow marker. After the second injection, the animals were killed and the lungs were excised and air dried at total lung capacity. The left lung was sliced into transverse planes and then sectioned into smaller blocks containing airways down to 1 mm in diameter. The blocks were then sectioned using a Vibratome and examined with a fluorescence microscope. Pulmonary and systemic blood flow markers were counted in airway walls, and the diameter of each airway was measured to determine the bronchial tissue volume. After a correction for the number of blood flow markers injected into each circulation, the average ratio of pulmonary to systemic blood flow markers seen in airway walls was 1:37, indicating that 97% of the blood supply to the intraparenchymal airways down to 1 mm in diameter was from the bronchial circulation. Furthermore, on the basis of a weighted least squares regression analysis, systemic (bronchial) blood flow per unit tissue volume increased as airway diameter decreased (P = 0.03).
本研究通过对4只犬使用15μm荧光微球和荧光显微镜，确定了全身（支气管）血流和肺血流对直径大于1mm的肺实质内气道的相对贡献。将一种颜色的荧光微球注入下腔静脉作为肺血流标记物，将另一种颜色的荧光微球注入左心室作为全身血流标记物。第二次注射后，处死动物，切除肺并在肺总量下进行空气干燥。将左肺切成横断面，然后切成包含直径达1mm气道的较小组织块。然后使用振动切片机对组织块进行切片，并在荧光显微镜下检查。在气道壁中计数肺血流和全身血流标记物，并测量每个气道的直径以确定支气管组织体积。在对注入每个循环的血流标记物数量进行校正后，在气道壁中观察到的肺血流与全身血流标记物的平均比例为1:37，这表明直径达1mm的肺实质内气道的97%血液供应来自支气管循环。此外，基于加权最小二乘回归分析，每单位组织体积的全身（支气管）血流随着气道直径的减小而增加（P = 0.03）。
