大通牦牛肺血管显微结构的增龄性变化特点

Characteristics of the age- related changes in the microstructures of the pulmonary vessels of Datong yaks

为了研究大通牦牛肺血管对高原低氧适应的组织学特点及发育学变化,试验选取4个年龄段（1日龄、30日龄、180日龄及成年）大通牦牛作为研究对象,以平原黄牛作对照,利用光镜技术和图像采集分析系统,比较大通牦牛和平原黄牛的肺细小动脉中膜厚度占血管外径的比（膜厚度比）,并进行定量分析。结果表明：大通牦牛的肺血管在发育过程中表现为随着血管管径的逐渐变细,平滑肌含量和平原黄牛相比越来越少;而在发育过程中,30日龄表现为一个相对特殊的阶段,主要表现为在30日龄大通牦牛肺血管中,直径〉100μm的血管在4个年龄段中平滑肌含量最少,而直径在〉50~≤100μm和直径≤50μm的血管中,30日龄的大通牦牛肺血管平滑肌含量最多。说明这些组织学的特征能够增强肺血管的收缩性和运送血液的能力,保证能量的传递和血液的供应,并且不易产生肺动脉高压,这是大通牦牛肺血管对低氧环境的组织学适应。

To investigate the changes in histological characteristics and development of the pulmonary vessels in Datong yaks under high - altitudehypoxic adaptation. One -day old, 30 -day old, 180 -day old and adult Datong yaks were chosen as research objectives while taking yellow cattle from plain area as control. Optical microscope technique and image sampling analysis were applied to compare the ratios of the membrane thickness to outer vascular diameters in pulmonary arterioles between Datong yaks and the yellow cattle from plain area, and then the compared results were quantitatively analyzed. The results showed that in the development process of pulmonary vessel, the smooth muscle content （SMC） of Datong yaks decreased more significantly compared with yellow cattle from plain area as the vessel diameter gradually got thinner; and the 30 -day old yaks were in a special stage during the development process; the SMC in the pulmonary vessel with the diameter greater than 100 μm in the yaks at 30 days of age was smallest among four different age stages; while the SMCs in the vessels with the diameters which ranged from greater than 50 μm to smaller than or equal to 100 μm and were smaller than 50 μm were greatest. The results indicate that these histological characteristics can enhance the contractility of the pulmonary vessel and the capacity of transferring blood, and ensure the energy transfer and blood supply without causing pulmonary arterial hypertension. This is histological adaptation of the pulmonary vessel of Datong yaks to hypoxia environment.