正常大鼠不同动脉血管应力-应变分布的比较

REGIONAL ARTERIAL STRESS-STRAIN DISTRIBUTIONS IN THE RAT REFERENCED TO THE ZERO-STRESS STATE

通过充压实验和无载荷状态及零应力状态，我们研究了 １６只雄性大鼠的胸主动脉、腹主动脉、左颈总动脉、左股动脉和左肺动脉的形态学和应力－应变分布特征，并比较了不同血管间的差异。结果表明，血管的内外周长、管壁和管腔面积、管壁厚度、管壁厚度与内半径之比以及在不同压力负荷下血管外直径的变化，五条动脉之间有显著差异（Ｐ＜０．０１）。展开角在肺动脉最大，而胸主动脉最小（Ｐ＜０．０１）。残余应变绝对值和残余应变梯度在股动脉最大，而在胸主动脉最小（Ｐ＜０．０１）。应力－应变关系分析证明，在周向上，股动脉最硬；在轴向上，胸主动脉最硬。而在这两个方向上，肺动脉最软。本实验表明，无论在形态学指数方面，还是在生物力学特征方面，五条动脉血管间都有显著差异。

To investigate the regional arterial stress-strain distributions referenced to the zero-stress state. Morphometry and stress-strain properties were studied in isolated segments of the thoracic aorta (T), abdominal aorta (A), left common carotid arteries (C), left femoral arteries (F) and the left pulmonary arteries (P) in 16 male Wistar rats. The distension test was performed as pressure-volume experiments. The dimensions of the outer wall were obtained from digitized images of the arterial segments at different pressures and at no-load and zero-stress states. The results showed that the morphometric data, such as inner and outer circumferential length, wall and lumen area, wall thickness, wall thickness-to-inner whins ratio and normalized outer diameter referenced to different pressures differed between the five arteries (p<0.01). The opening angle was largest in the pulmonary artery and smallest in thoracic aorta (p<0.01). The absolute value of both the inner and outer residual strain and the residual strain gradient were largest in the femoral artery and smallest in the thoracic aorta (p<0.01). In circumferential and longitudinal direction, the arterial wall was stiffest in the femoral artery and in the thoracic aorta respectively, and softest in the pulmonary artery. These results show that the morphometry and biomechanical properties distribution on these five different arterial segments was much different.