Mizuuchi T, Kida K, Fujino Y
Pulmonary Division, Tokyo Metropolitan Geriatric Hospital, Japan.
Exp Gerontol. 1994 Sep-Oct;29(5):553-67. doi: 10.1016/0531-5565(94)90038-8.
Observations by light microscopic morphometry and scanning electron microscopy were performed on the lungs from 86 specific pathogen-free Fischer 344 male rats between 1 day and 32 months of age. The distribution curve of the mean chord length of the gas exchanging area appeared as a single peak (approximately 70 microns) at day 1, and two peaks (approximately 50 and 90 microns) were seen at day 7 when the first alveoli appeared. At 3 months of age, the distribution curve peaks began to decrease gradually, becoming more flattened with a wide base to a maximum 200 microns. Between 27 and 32 months of age, ductectasia occurred and the alveolar surface appeared more irregular and rough, but no destruction of the alveolar wall was observed. From these observations, it was concluded that the first alveoli appear by 7 days of age in male Fischer 344 rats, that the alveolar size gradually increases after 3 months of age, and that ductectasia appears after 27 months of age. These changes might reflect changes in the matrix of the alveolar walls due to nutritional deterioration in old age, concomitant with cellular atrophy of this zone.
对86只1日龄至32月龄的无特定病原体Fischer 344雄性大鼠的肺组织进行了光镜形态计量学观察和扫描电镜观察。气体交换区域平均弦长的分布曲线在1日龄时呈现单峰（约70微米），在第7天首次出现肺泡时可见两个峰（约50和90微米）。3月龄时，分布曲线的峰值开始逐渐下降，变得更加扁平且基部变宽，最大可达200微米。在27至32月龄时，出现了细支气管扩张，肺泡表面显得更加不规则和粗糙，但未观察到肺泡壁的破坏。从这些观察结果得出结论，雄性Fischer 344大鼠在7日龄时出现首批肺泡，3月龄后肺泡大小逐渐增加，27月龄后出现细支气管扩张。这些变化可能反映了老年时由于营养恶化导致的肺泡壁基质变化，同时伴有该区域的细胞萎缩。
