大通牦牛肺微血管的增龄性变化特点

Characteristics of age-related changes in pulmonary microvessels of the Datong yak

为了阐明高原牦牛肺血管随海拔升高对高原低氧环境适应的结构学特点及发育学特点,试验采用免疫组织化学染色法对1日龄、30日龄、180日龄、成年牦牛肺血管内皮生长因子(VEGF)的分布进行了研究。结果表明:VEGF大量分布于导气部上皮的Clara细胞胞质和伴行肺动脉内皮细胞胞质内,在导气部上皮的纤毛细胞、管壁平滑肌内也有分布,VEGF在肺动脉平滑肌中的分布随着管径的减小而减少;在呼吸部上皮内没有VEGF分布,仅在肺泡壁有散在分布。而大通牦牛肺组织VEGF的灰度值随着年龄的增长表现为先降低再升高,山东黄牛肺组织VEGF的灰度值随着年龄的增长表现为逐渐升高,而相同发育阶段大通牦牛肺组织VEGF灰度值极显著高于山东黄牛肺组织VEGF灰度值。表明低氧能刺激大通牦牛肺导气部和肺动脉内的VEGF含量增加,从而对牦牛肺脏新生微血管的形成产生影响,这可能是牦牛肺脏能适应高原低氧环境的重要因素。

To clarify the structural characteristics and developmental characteristics of pulmonary vessels of plateau yak in adaptation to high altitude hypoxia environment with the increase of altitude, distribution of the pulmonary vascular endothelial growth factors （VEGF） of one - day old, 30- day old, 180- day oldand adult yaks were studied using an immunohistochemical staining method. The results showed that, the VEGF massively distributed in the Clara cell cytoplasm from the epithelium in the conducting portion and the endothelial cell cytoplasm of concomitant pulmonary artery, and also distributed in the ciliated cells and vascular wall smooth muscle from the epithelium in the conducting portion. The distribution of VEGF in pulmonary artery smooth muscle decreased with the decrease of vascalar diameter, and there was no VEGF distribution in the epithelium from respiratory portion, and VEGF only scattered in the alveolar walt. The gray value of VEGF in lung tissue of Datong yak presented a decrease at first and then an increase with the increase of age, and the gray value of VEGF in lung tissue of Datong yak presented a gradual increase, while the gray value of VEGF in lung tissue of Datong yak was extremely significantly higher than that of Shandong cattle at the same developmental stage： The results indicate that hypoxia can Stimulate the increase of VEGF contents in the pulmonary conducting portion and pulmonary artery, which has an impact on the formation of newborn microvessels from the lung of Datong yak; this may be an important factor that the lung of yak can adapt to high altitude hypoxia environment.