门静脉性肺动脉高压犬重建肺动脉超微结构的实验研究

Experimental research on the reconstruction of pulmonary artery ultrastructure in the beagle model with portopulmonary hypertension

目的探讨门静脉性肺动脉高压(portopulmonary hypertension,PPHTN)犬肺动脉压力和肺血管超微结构。方法健康同龄同种系比格犬30只,随机分为PPHTN模型组和正常对照组,每组15只。模型组采取门静脉内注射葡聚糖微球栓塞制备PPHTN模型,成功建立模型后2、4、6、8、10、12周时,测量2组犬肺动脉压力,12周末取2组肺动脉行组织病理检查,观察2组犬肺动脉的超微结构,对肺血管的病理改变进行分级和图像计量学分析。结果 PPHTN模型组犬肺血管可见中膜增厚和动脉管壁肥厚等血管重构现象;PPHTN模型组犬肺动脉的肺小动脉中膜厚度[(111.41±41.05)mm]、肺小动脉密度[(4.51±1.61)μg/mm3]、血管壁面积/血管总面积[(80.80±7.99)%]及建模后12周肺动脉压力[(9.06±1.15)kPa]均明显高于对照组[(72.27±26.98)mm、(2.21±1.05)μg/mm3、(61.10±10.11)%、(1.53±0.89)kPa],差异有统计学意义(P<0.05)。结论 PPHTN犬肺动脉的超微结构可见血管重塑,肺动脉压力增高及血管内径减小是门脉性高压引起肺损伤的超微病理学基础,急性肺高压和急性肺损伤与门静脉高压存在密切关联。

Objective To explore the pulmonary artery pressure and pulmonary vessel ultrastructure in the beagle models with portopulmonary hypertension（PPHTN）.Methods Thirty healthy beagles of the same age and race were randomly divided into PPHTN model group and control group,with 15 beagles in each group.PPHTN model was established by portal venous injection of dextran microspheres.The pulmonary artery pressure was measured in 2,4,6,8,10 and 12weeks after establishing models in PPHTN model group and at the same time points in control group.The pulmonary artery tissue was obtained in 12 weeks to observe the ultrastructure in two groups,and the pathological changes of pulmonary vessel was classified and imaging metrologically analyzed.Results PPHTN model group was found vascular remodeling of thickening tunica media and artery wall.The intima-media thickness of pulmonary arteriole（（111.41±41.05）mm）was significantly thicker,the density of pulmonary arteriole（（4.51±1.61）μg/mm^3）was larger,the vascular wall area/total area of blood vessel（（80.80±7.99）%）was larger and pulmonary artery pressure after 12 weeks of modeling（（9.06±1.15）kPa）was higher in PPHTN model group than those in control group（（72.27±26.98）mm,（2.21±1.05）μg/mm^3,（61.10±10.11）%,（1.53±0.89）kPa）（P〈0.05）.Conclusion The vascular remodeling could be found in the ultrastructure of PPHTN beagles.The increased pulmonary artery pressure and decreased blood vessel diameter are the pathological basis of portal hypertension induced lung injury.Acute pulmonary hypertension and acute lung injury are closely correlated with portal hypertension.