Alterations in structure of elastic laminae of rat pulmonary arteries in hypoxic hypertension.
Alterations in structure of elastic laminae of rat pulmonary arteries in hypoxic hypertension.
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DOI：
10.1152/jappl.1996.81.5.2147
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发表时间：
1996-11
影响因子：
3.3
通讯作者：
S. Q. Liu
中科院分区：
文献类型：
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作者：
S. Q. Liu
采用电镜研究了缺氧性高血压对大鼠肺门肺动脉（PAs）弹力层重塑过程的影响。大鼠暴露于缺氧（10％O2）下0.5、2、6、12、48、96、144和240小时。根据 PA 壁拉应力的变化，检查并分析了 PA 弹性层结构的变化。 PA血压在缺氧的最初几个小时内迅速升高，并在2天内达到稳定水平，而PA壁拉应力最初由于血压升高而增加，然后由于血管壁增厚而在48小时后下降，并在4天后恢复到控制水平。与这些变化相关的是，在正常对照大鼠中呈现均匀的弹性层，在缺氧早期转变为由随机定向的细丝和水肿内容物组成的结构，并且体积增加，并在4天后恢复其均匀的外观和正常体积。弹性层的变化与拉应力的变化相关。这些变化与 PA 刚度的瞬时下降有关。在给予硝苯地平的缺氧大鼠中，尽管持续处于缺氧状态，但血压、拉应力或 PA 弹性层的结构没有发现变化。这些结果表明，PA 壁中拉伸应力的改变在弹性层结构变化的启动和调节中发挥着关键作用，并且这些变化可能有助于缺氧高血压中 PA 机械性能的改变。
The effect of hypoxic hypertension on the remodeling process of the elastic laminae of the rat hilar pulmonary arteries (PAs) was studied by electron microscopy. Rats were exposed to hypoxia (10% O2) for periods of 0.5, 2,6,12,48,96,144, and 240 h. Changes in the structure of the PA elastic laminae were examined and analyzed with respect to changes in the PA wall tensile stress. The PA blood pressure increased rapidly within the first several hours of hypoxia and reached a stable level within 2 days, whereas the PA wall tensile stress increased initially due to elevated blood pressure and then decreased after 48 h due to vessel wall thickening and returned to the control level after 4 days. In association with these changes, the elastic laminae, which appeared homogeneous in normal control rats, changed into structures composed of randomly oriented filaments and edematous contents with an increase in the volume during the early period of hypoxia and regained their homogeneous appearance and normal volume after 4 days. The changes in the elastic laminae were correlated with changes in the tensile stress. These changes were associated with a transient decrease in the stiffness of the PAs. In hypoxic rats given nifedipine, no change was found in the blood pressure, the tensile stress, or the structure of the elastic laminae of the PAs despite continuous exposure to hypoxia. These results suggested that altered tensile stress in the PA wall played a critical role in the initiation and regulation of structural changes in the elastic laminae and that these changes might contribute to alterations in the mechanical properties of the PA in hypoxic hypertension.