Haberthür David, Barré Sébastien F, Tschanz Stefan A, Yao Eveline, Stampanoni Marco, Schittny Johannes C
Institute of Anatomy, University of Bern, Bern, Switzerland;
J Appl Physiol (1985). 2013 Nov 1;115(9):1379-87. doi: 10.1152/japplphysiol.00642.2013. Epub 2013 Aug 22.
The small trees of gas-exchanging pulmonary airways, which are fed by the most distal purely conducting airways, are called acini and represent the functional gas-exchanging units. The three-dimensional architecture of the acini has a strong influence on ventilation and particle deposition. Due to the difficulty in identifying individual acini on microscopic lung sections, the knowledge about the number of acini and their biological parameters, like volume, surface area, and number of alveoli per acinus, are limited. We developed a method to extract individual acini from lungs imaged by high-resolution synchrotron radiation-based X-ray tomographic microscopy and estimated their volume, surface area, and number of alveoli. Rat acini were isolated by semiautomatically closing the airways at the transition from conducting to gas-exchanging airways. We estimated a mean internal acinar volume of 1.148 mm(3), a mean acinar surface area of 73.9 mm(2), and a mean of 8,470 alveoli/acinus. Assuming that the acini are similarly sized throughout different regions of the lung, we calculated that a rat lung contains 5,470 ± 833 acini. We conclude that our novel approach is well suited for the fast and reliable characterization of a large number of individual acini in healthy, diseased, or transgenic lungs of different species, including humans.
由最远端的纯传导性气道供血的气体交换性肺气道的小树状结构称为腺泡，它代表功能性气体交换单位。腺泡的三维结构对通气和颗粒沉积有很大影响。由于在显微镜下的肺切片上识别单个腺泡存在困难，关于腺泡数量及其生物学参数（如每个腺泡的体积、表面积和肺泡数量）的知识有限。我们开发了一种方法，可从基于高分辨率同步辐射的X射线断层显微镜成像的肺中提取单个腺泡，并估计它们的体积、表面积和肺泡数量。通过在传导性气道向气体交换性气道过渡处半自动封闭气道来分离大鼠腺泡。我们估计腺泡的平均内部体积为1.148立方毫米，平均腺泡表面积为73.9平方毫米，每个腺泡平均有8470个肺泡。假设在肺的不同区域腺泡大小相似，我们计算出大鼠肺包含5470±833个腺泡。我们得出结论，我们的新方法非常适合快速可靠地表征不同物种（包括人类）的健康、患病或转基因肺中的大量单个腺泡。
