小鼠胸主动脉壁内弹性纤维和胶原纤维的发育规律

Developmental pattern of elastic and collagen fibers in the thoracic aorta wall of mice

目的明确细胞外基质弹性纤维和胶原纤维在不同年龄阶段鼠主动脉中的表达规律。方法分别采用Van Gieson染色、弹性蛋白免疫荧光染色和Masson染色,观察小鼠胸主动脉在不同年龄阶段(出生后3天、3月、6月和16月龄)的弹性膜形成、弹性蛋白和胶原纤维的表达变化;采用透射电子显微镜术观察12月和18月龄大鼠腹主动脉细胞外基质弹性纤维和胶原纤维的变化。结果出生后3天小鼠胸主动脉的弹性纤维没有形成完整的弹性膜,3月已初步形成完整的弹性膜,6月有5~7层弹性膜,16月弹性膜呈片段化;出生后3天弹性蛋白的表达低,3月呈上升趋势,6月最高,16月减少;出生后3天胶原纤维含量少,随着年龄增长,胶原纤维的含量增加。透射电子显微镜技术显示12月大鼠腹主动脉细胞外基质以弹性纤维为主,胶原纤维含量较少;而18月大鼠胶原纤维含量增加。结论细胞外基质弹性纤维和胶原纤维在不同年龄小鼠主动脉壁内的表达规律不同。

Objective To figure out the expression pattern of extracellular matrix components, elastic and collagen fibers, in thoracic aorta wall of mice at different ages. Methods Van Gieson staining, elastin immunofluorescence staining and Masson staining were performed for detection of the changes of elastic membrane formation, elastic and collagen fibers expression in the mouse thoracic aorta at different ages(3 d, 3 m, 6 m and 16 m after birth). In addition, transmission eletromicroscopy was employed for investigating the changes of extracellular matrix elastic and collagen fibers in the abdominal aorta of 12 m-old and 18 m-old rats. Results Elastic fibers in the thoracic aorta did not form a complete elastic laminae in 3 d old mice after birth, but initially formed a complete one in 3 m old mice. In 6 m old mice, there were 5-7 layers of elastic laminae, and in 16 m old mice, the elastic membrane was fragmented. In 3 d old mice after birth, elastin content was low, then increased in 3 m old mice, and peaked in 6 m old mice, while decreased in 16 m old mice. Collagen content was low in 3 d old mice after birth, and increased with age. Transmission eletron microscopy showed in the abdominal aorta of 12 m old rats, the extracellular matrix contained abundant elastic fibers, but less collagen fibers. However, in 18 m old rats collagen fibers were apparently increased. Conclusion The extracellular matrix elastic and collagen fibers in aortic wall of mice have different expression patterns at different ages.