Rachev A, Greenwald S E, Kane T P, Moore J E, Meister J J
Institute of Mechanics, Bulgarian Academy of Sciences, Sofia, Bulgaria.
Biorheology. 1995 Jul-Aug;32(4):473-85. doi: 10.1016/0006-355X(95)00024-4.
The variation of wall stress distribution with age in the thoracic and abdominal aortas of normotensive rats was studied. Dimensions of the zero-stress configurations were measured at the ages of 4, 8, 12, 20, and 52 weeks. Using data from previously published inflation tests, the circumferential stress-strain relationship was obtained in each age group. The calculated stress distribution showed that the average circumferential stress remained practically constant after the age of 20 weeks. The circumferential stress at the innermost part of the arterial wall was greater than the stress at the outermost part, but the difference was maintained at a moderate level with adjustments in the zero-stress configuration. It is speculated that, after the age of 20 weeks, changes in arterial geometry and rheological properties tend to maintain a constant stress distribution under varying conditions of loading. This distribution was achieved by enhanced growth at the inner part of the media in comparison with the growth at its outer margins and suggests that during development and maturity, the growth of the aorta is modulated by circumferential stress.
研究了正常血压大鼠胸主动脉和腹主动脉壁应力分布随年龄的变化。在4、8、12、20和52周龄时测量了零应力构型的尺寸。利用先前发表的膨胀试验数据，获得了每个年龄组的周向应力-应变关系。计算得到的应力分布表明，20周龄后平均周向应力基本保持恒定。动脉壁最内层的周向应力大于最外层的应力，但通过调整零应力构型，差异保持在适度水平。据推测，20周龄后，动脉几何形状和流变特性的变化倾向于在不同加载条件下维持恒定的应力分布。这种分布是通过中膜内层相对于其外缘的生长增强来实现的，这表明在发育和成熟过程中，主动脉的生长受周向应力调节。
