CHANGES OF ZERO-STRESS STATE OF RAT PULMONARY-ARTERIES IN HYPOXIC HYPERTENSION
CHANGES OF ZERO-STRESS STATE OF RAT PULMONARY-ARTERIES IN HYPOXIC HYPERTENSION
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DOI：
10.1152/jappl.1991.70.6.2455
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发表时间：
1991-06-01
影响因子：
3.3
通讯作者：
LIU, SQ
中科院分区：
文献类型：
--
作者：
FUNG, YC;LIU, SQ
本文测定了25只正常对照组和38只缺氧性肺动脉高压大鼠从主干至管腔直径约60微米的主肺动脉的零应力状态。将大鼠置于常压、含10%O2-90%N_2的低氧舱内，建立大鼠肺动脉高压模型。每个血管的零应力状态是通过首先将血管横切成一系列环，然后将每个环径向切割成扇形，然后将每个环开口成扇形，其特征是开口角度定义为从内壁(内皮)的中点到内壁尖端的两条线之间的夹角。而在肺动脉高压形成过程中，肺动脉压呈单调性升高，但张开角遵循不同的过程；例如，在暴露于低氧后的时间0(对照)和2、12、28、96、144、240、480和720小时处的肺干张开角度的值(平均值+/-SD)分别为294+/-30度、378+/-24度、385+/-12度、374+/-11度、246+/-63度、267+/-49度、193+/-19度、195+/-83度和239+/-38度。动脉上其他地方的趋势相似，但幅度不同。在这段时间内，可见内膜水肿和增厚。动脉内膜在48~240h增厚迅速，240~720h增厚较慢，之后外膜增厚，96h左右超过内膜增厚，由此认为，肺动脉零应力状态的改变与管壁的不均匀重塑有关，表现为不同层次的水肿、气泡和增厚。
Zero-stress state of the main pulmonary arteries, from the main trunk to a vessel with a lumen diameter approximately 60-mu-m, was determined in 25 normal control and 38 hypoxic pulmonary hypertensive rats. Pulmonary hypertension was induced by placing the rats in a hypoxic chamber with 10% O2-90% N2 at atmospheric pressure. The zero-stress state of each vessel was obtained by first cutting the vessel transversely into a series of rings and then cutting each ring radially, whereupon the ring opened into a sector, which is characterized by an opening angle defined as the angle subtended between two lines originating from the midpoint of the inner wall (endothelium) to the tips of the inner wall. Whereas the pulmonary blood pressure increased monotonically during the development of pulmonary hypertension, the opening angle followed a different course; e.g., the values (means +/- SD) of the opening angle at the pulmonary trunk at times 0 (control) and 2, 12, 28, 96, 144, 240, 480, and 720 h after exposure to hypoxia are, respectively, 294 +/- 30-degrees, 378 +/- 24-degrees, 385 +/- 12-degrees, 374 +/- 11-degrees, 246 +/- 63-degrees, 267 +/- 49-degrees, 193 +/- 19-degrees, 195 +/- 83-degrees, and 239 +/- 38-degrees. Trends at other places on the artery are similar, but the magnitudes differ. In this period of time, intimal edema and thickening were found. The intima media thickened rapidly from 48 to 240 h and then more slowly from 240 to 720 h. Adventitia thickened later; its thickness exceeded that of the intima media at approximately 96 h. Thus the change of zero-stress state of the pulmonary arteries are seen to be related to the nonuniform remodeling of the vessel wall as revealed by the edema, blebs, and thickening of different layers.