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bioRxiv · 10.1101/2020.12.11.421032

Analysis of the area and the number of pulmonary alveoli through the normal aging process in CD1 mouse

Ortega-Martinez, M.·Gutierrez-Arenas, E.·Gutierrez-Davila, V.·Niderhauser-Garcia, A.·Cerda-Flores, R. M.·Jaramillo-Rangel, G.
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Abstract

During the aging process, the lung exhibits structural changes accompanied by a decline in its function. The related information currently available is still scarce and contradictory. In addition, changes in some pulmonary parameters through aging process are species- and strain-dependent. The aim of this study was the assessment of the area and the number of pulmonary alveoli through the normal aging process in CD1 mouse. Paraffin-embedded sections of lungs from CD1 mice at age of 2, 6, 12, 18, or 24 months were stained with hematoxylin and eosin and examined using a light microscope. Images were captured using a camera linked to an image analysis software to measure areas and count alveoli. There was a significant difference in the alveolar area among the ages analyzed (F=87.53, Sig.=0.000). The alveolar area of the 6-, 12-, 18-, and 24-month-old mice was significantly greater (all p values < 0.001) than in mice at 2 months of age. Also, the alveolar number was significantly different among the ages tested (F=3.21, Sig.=0.023). The number of alveoli in mice at 2 months of age was greater than in mice at all other age groups, reaching statistical significance when compared with the 6-, 12-, and 18-month-old mice (p values of 0.044, 0.014, and 0.002, respectively). Thus, we observed an increase in alveolar area and a decrease in alveolar number through the aging process. This information might be useful to understand pathologic changes underlying susceptibility of elderly individuals to chronic lower respiratory tract diseases.

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Ortega-Martinez, M., Gutierrez-Arenas, E., Gutierrez-Davila, V., Niderhauser-Garcia, A., Cerda-Flores, R. M., Jaramillo-Rangel, G.. 2020-12-11. Analysis of the area and the number of pulmonary alveoli through the normal aging process in CD1 mouse. https://doi.org/10.1101/2020.12.11.421032

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