Han Hui, Lam David C C, Huang Wei
Dept. of Health Technology and Informatics, Hong Kong Polytechnic University, Kowloon, Hong Kong.
Mol Cell Biomech. 2012 Dec;9(4):295-307.
The objective of our study was to study the effect of danshen, a Chinese herbal medicine known to prevent hypertension, on the zero-stress state of rat's abdominal aorta. The zero-stress state of a blood vessel represents the release of residual stress on the vessel wall, and is the basic configuration of blood vessel affected solely by intrinsic parameters. At the in vivo state, the rat's abdominal aorta was subjected to blood pressure and flow and longitudinal stress. After dissecting from the abdominal aorta, the aortic specimens were cut into small rings at no-load state, in which the internal pressure, external pressure, and longitudinal stress in a short ring-shaped segment were all zero; by cutting radially to release the residual stress in the wall, the vessel ring opened up into a sector quickly, and the sector's configuration would not change at 20 min after cutting and was defined as the zero-stress state of a blood vessel, which was characterized by its residual strain and opening angle. Then aqueous extract of danshen prepared with methanol was added in the Krebs solution, and the changes of the aorta's zero-stress state were monitored by taking photos routinely for analysis to determine the opening angle and residual strain. Additionally, other sets of samples were tested in a Norepinephrine-Krebs solution as positive control or a Krebs solution as negative control, respectively. It was demonstrated that the zero-stress state of rat's abdominal aorta was affected by danshen extract and norepinephrine in two different patterns, while the Krebs solution did not have similar effects. The present work provides a new approach to study the anti-hypertension effect and mechanism of danshen.
我们研究的目的是探讨丹参（一种已知可预防高血压的中药）对大鼠腹主动脉零应力状态的影响。血管的零应力状态代表血管壁上残余应力的释放，是仅受内在参数影响的血管基本构型。在体内状态下，大鼠腹主动脉承受血压、血流和纵向应力。从腹主动脉分离后，将主动脉标本在无负荷状态下切成小环，其中短环形段的内压、外压和纵向应力均为零；通过径向切割释放壁内残余应力，血管环迅速展开成扇形，切割后20分钟扇形构型不变，定义为血管的零应力状态，其特征为残余应变和开口角度。然后将用甲醇制备的丹参水提取物加入Krebs溶液中，通过定期拍照监测主动脉零应力状态的变化以进行分析，确定开口角度和残余应变。此外，分别在去甲肾上腺素-Krebs溶液中作为阳性对照或在Krebs溶液中作为阴性对照对其他组样本进行测试。结果表明，丹参提取物和去甲肾上腺素以两种不同模式影响大鼠腹主动脉的零应力状态，而Krebs溶液没有类似作用。本研究为探讨丹参的抗高血压作用及机制提供了一种新方法。
