Microscopic Study of the Lungs of Sprague-Dawley Rats from Various Ages of Postnatal and Aging Periods | Science Publications

OnLine Journal of Biological Sciences

Isabella Kurnia Liem¹  Ria Margiana¹  Jeanne Adiwinata Pawitan¹ 

关键词: Lung Parenchyma;    Pulmonary Postnatal;    Lung Aging;    Lung Morphology;   

DOI  :  10.3844/ojbsci.2015.74.82

学科分类：生物科学（综合）

来源: Science Publications

【 摘 要 】

Physiologicalchanges in postnatal and aging lung are associated with a variety ofmicroscopic changes in the lung, especially the alveolar lung tissue, both inthe interstitial and epithelial component. Interstitial tissue of the lung willincrease in thickness that is supposed to be due to changes in fibercomposition, particularly collagen. However, the exact changes are still underdebate and the underlying process is still unclear. The epithelial componentthat experiences changes is type II alveolar cells or pneumocyte II (surfactantproducing cells). The ratio of pneumocyte II against pneumocyte I is expectedto decline with age. This decrease will certainly affect their function inmaintaining pulmonary surfactant supply. To maintain normal vital functions andsynthesis of surfactant, lung tissue is also dependent on the availability ofglucose because glucose is the fundamental building blocks of glycerol backboneof surfactant. In the aging process, accumulation of glycogen in the brain,skeletal muscle and kidney has been reported, so glycogen is supposed as amarker of cell aging (senescence cells). Nevertheless, studies on glycogenaccumulation in lung tissue in aging have not been reported. This study aims toobserve the microscopic changes in lung tissue, both in interstitial tissue andalveolar epithelial cell (pneumocyte II) in postnatal and aging Sprague-Dawleyrats. This was an observational analytical study to determine the correlationbetween age and the amount of interstitial collagen fibers, the thickness ofthe interstitial tissue, glycoproteins and glycogen accumulation in theinterstitial component, the ratio of pneumocyte II and I and accumulation ofglycogen in pneumocyte II. Correlation tests were performed with Spearmancorrelation test (p≥0.05) using SPSS 17 for Windows. The study wasconducted on Sprague-Dawley rats aged 2 days (n = 6), 4 days (n = 6), 10 days(n = 6), 16 days (n = 6), 3-4 months (n = 6) and more than 12 months (n = 6).Lung tissue was cut with a thickness of 5 μm and stained with Mason's trichrometo visualize collagen and with periodic acid Schiff to visualize glycoproteinsand glycogen. There was a low correlation between age and proportion ofinterstitial tissue (r = 0.291), the accumulation of glycoproteins in theinterstitial (r = 0.300) and accumulation of glycogen in pneumocyte II (r =266). There was a moderate correlation between age and the amount of interstitialcollagen fibers (r = 0.687), but there was no correlation between age andpneumocyte II/I ratio (r = 0.123). With increasing age, the interstitial lungtissue would increase in thickness, collagen fibers and glycoproteins andglycogen accumulation. While in the lung epithelium, no evidence of decline inthe ratio of pneumocyte II/I, but there is an increasing accumulation ofglycogen in pneumocyte II.

【 授权许可】

Unknown