We are thankful for the support of the Swiss National Science Foundation (grants 310030-125397 and CR23I2_135550).
Efficient estimation of the total number of acini in adult rat lung
Article first published online: 4 JUL 2014
© 2014 The Authors. Physiological Reports published by Wiley Periodicals, Inc. on behalf of the American Physiological Society and The Physiological Society.
This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.
Volume 2, Issue 7, July 2014
How to Cite
Efficient estimation of the total number of acini in adult rat lung, Physiol Rep, 2 (7), 2014, e12063, doi: 10.14814/phy2.12063, , , ,
- Issue published online: 3 JUL 2014
- Article first published online: 4 JUL 2014
- Manuscript Accepted: 30 MAY 2014
- Manuscript Revised: 25 MAY 2014
- Manuscript Received: 12 MAR 2014
- Swiss National Science Foundation. Grant Numbers: 310030-125397, CR23I2_135550
- pulmonary acinus;
- stereological analysis;
- X-ray microcomputed tomography;
- X-ray tomographic microscopy
Pulmonary airways are subdivided into conducting and gas-exchanging airways. An acinus is defined as the small tree of gas-exchanging airways, which is fed by the most distal purely conducting airway. Until now a dissector of five consecutive sections or airway casts were used to count acini. We developed a faster method to estimate the number of acini in young adult rats. Right middle lung lobes were critical point dried or paraffin embedded after heavy metal staining and imaged by X-ray micro-CT or synchrotron radiation-based X-rays tomographic microscopy. The entrances of the acini were counted in three-dimensional (3D) stacks of images by scrolling through them and using morphological criteria (airway wall thickness and appearance of alveoli). Segmentation stopper were placed at the acinar entrances for 3D visualizations of the conducting airways. We observed that acinar airways start at various generations and that one transitional bronchiole may serve more than one acinus. A mean of 5612 (±547) acini per lung and a mean airspace volume of 0.907 (±0.108) μL per acinus were estimated. In 60-day-old rats neither the number of acini nor the mean acinar volume did correlate with the body weight or the lung volume.