动力性肺动脉高压幼犬模型中肺动脉压力与血管结构的关系

Relationship between pressure and structure of experimental pulmonary artery hypertension in puppies

目的 探讨肺动脉压力与结构关系 .方法 实验幼犬 15只 ,分 2组 .组 1为分流组 ( n=12 ) ,组 2为正常对照组 ( n=3) .分流后 90 d两组进行血流动力学检测后 ,放血处死 ,肺组织切片行病理学检测 .结果 1组 1左下肺动脉压( PL L PA)、左下肺血管阻力 ( L L PVR)及肺血流量 ( PBF)显著升高 ( P <0 .0 1) ,右肺动脉压 ( PRPA)也有升高 ,但不及PL L PA显著 . 2分流犬左下肺动脉出现平滑肌细胞显著增生并向肺动脉远端延伸 ,肌性动脉 ( MA)、部分肌性动脉( PMA)数量增多 ,非肌性动脉 ( NMA)数量减少 ,弹力、胶原纤维增多 ,血管中膜及内膜增厚 ,部分血管腔闭塞甚至出现血管丛样改变 ,分流犬右下肺动脉仅出现轻度增生 ,且仅限于中膜 .结论 肺动脉压力的升高可导致肺动脉结构重塑 ,肺动脉高压程度不同 ,所造成的肺动脉病理改变也不同 .而肺动脉的病理改变又导致肺循环阻力的上升 ,从而导致肺动脉压力的进一步升高 。

AIM To explore the relationship between the pressure and the structure of pulmonary artery. METHODS Experimental puppies were divided into 2 groups: Shunted group (n=12), and the normal young dogs group (n=3). The pathologic examination of pulmonary artery (PA) was done after hemodynamic changes were measured and recorded on the 90th day. RESULTS ① The pressure, resistance and the blood flow of the lower left pulmonary artery (PLLPA, LLPVR and PBF) were heightened (P<0.01). The pressure of right pulmonary artery (PRPA) was also increased , but not so remarkable as PLLPA. ② The structure of lower left pulmonary artery was altered observably, and the SMC proliferated and extended to the distance. The muscle artery (MA) and partially muscle artery (PMA) increased, but the nonmuscle artery (NMA) reduced. The collagen and the elastic fibers were increased in arterioles. The intima and media were proliferous and hypertrophic, and the obliterations and the plexiform were observed in some arterioles. However, the changes of right pulmonary artery of model dogs were much milder than those of lower left pulmonary artery and only observed in media. CONCLUSION The increased of pulmonary artery pressure (PAP) resulted in the remodeling of pulmonary artery, The different degree of PAP reduced the different remodel of PA, and the pathologic changes of PA led to a further hoisting of pulmonary pressure. Both are the causes and effects of each other, and result in a malignant cycle.