藏猪适应高原低氧环境的肺脏血管铸型特征

Characteristics of pulmonary vascular casting in Tibetan pigs adapted to the hypoxic environment at high altitude

为从解剖学水平阐明藏猪肺脏响应高原低氧环境的结构特征。本研究分别采集藏猪及杜长大三元杂交猪的左肺,制作血管铸型标本,测定上、下叶动脉主干及其分支管径,并通过扫描电镜观察分析血管内壁特征。结果显示,藏猪和杂交猪肺脏动脉结构均呈"树枝状",动脉血管经Ⅰ~Ⅳ级分支后发出毛细血管,藏猪肺动脉各级分支管径均小于杂交猪,但其毛细血管相对丰富。通过分析不同群体肺脏动脉及其分支各部位管径与肺脏质量的相对值(T/W)发现,藏猪群体T/W值均显著高于杂交猪群体(P<0.05),较高海拔的甘南藏猪群体、永登杂交猪群体的T/W值均分别高于较低海拔的泾川藏猪群体和杂交猪群体,但差异均不显著。扫描电镜观察发现,甘南藏猪微血管表面存在"环形缩窄"结构和呈"梭形"的内皮细胞核压痕,其数量明显多于低海拔藏猪和杂交猪。因而推断藏猪肺脏较粗的动脉及其分支和发达的毛细血管网有助于提高血流量,进而增加其供氧能力;血管表面较多的"环形缩窄"结构和内皮细胞核"梭形"压痕表明毛细血管发达的前括约肌可增强血管收缩能力,从而保证肺脏中的血氧供应得以快速高效运行。

To elucidate the structural characteristics of the lungs of Tibetan pigs in response to the plateau hypoxic environment from the anatomical level.The left lungs of Tibetan pigs and hybrid pigs were collected,and vascular cast specimens were prepared.The upper and lower arterial trunks and their branch diameters were measured,and the characteristics of the inner wall of the blood vessels were analyzed by scanning electron microscopy.The results showed that the structure of the pulmonary arteries of Tibetan and hybrid pigs was"dendritic."Arterial blood vessels emitted capillaries after branching from gradesⅠtoⅣ.The diameter of the branches of the pulmonary arteries of Tibetan pigs was less than that of hybrid pigs,but their capillary vessels were relatively abundant.By analyzing the relative values(T/W)of the diameter of the pulmonary artery and its branches and the weight of the lungs in different populations,it was found that the T/W values of the Tibetan pig population were significantly higher(P<0.05)than that of the hybrid pig population.The T/W values of the Gannan Tibetan pig population and the Yongdeng hybrid pig population were higher than those of the Jingchuan Tibetan pig population and the hybrid pig population at lower altitudes,but the differences were not significant.Scanning electron microscopy observations revealed that there were"ring-narrowed"structures and"fusiform"endothelial cell nuclear indentations on the surface of the microvessels of Gannan Tibetan pigs,the number of them was significantly more than that of low-altitude Tibetan pigs and hybrid pigs.It is believed that the thicker arteries and their branches and the developed capillary network of Tibetan pig lungs help to increase blood flow and thus increase its oxygen supply capacity;more"ring-narrowed"structures on the surface of blood vessels and"spindle"endothelial cell nuclear indentations show that the developed sphincter of the capillaries can enhance the vasoconstriction ability,thereby ensuring the rapid and efficient operation of blood oxygen supply in the lungs.