Differential structural adaptation to haemodynamics along single rat cremaster arterioles
Differential structural adaptation to haemodynamics along single rat cremaster arterioles
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DOI：
10.1113/jphysiol.2002.035907
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发表时间：
2003-04-15
影响因子：
5.5
通讯作者：
VanBavel, E
中科院分区：
文献类型：
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作者：
Bakker, ENTP;Versluis, JP;VanBavel, E
我们测试的假设，在生理条件下，小动脉匹配其直径的水平的剪切应力。在大鼠提睾肌的一级小动脉段获得血流动力学和解剖学数据。沿着沿着这段长度约为10 mm的血管，局部血压从上游的68 +/- 4 mmHg降至下游的54 +/- 3 mmHg（n = 5）。脉压从上游8.2 +/- 1.3 mmHg降至下游4.1 +/- 0.6 mmHg。在相同的位置，在体内测量到小动脉直径的增加，从上游179 +/- 4 μ M增加到下游203 +/- 4 μ M（n = 10）。最大扩张血管的体外压力-直径关系显示，在15-125 mmHg压力范围内，下游段的被动直径大于上游段（n = 18）。上游与下游位置的壁应力相似：266 +/- 16 vs. 260 +/- 14 mN mm（-2）。但是，剪切应力沿动脉从30 +/- 5降至21 +/- 5 dyn cm（-2）（3.0 +/- 0.5降至2.1 +/- 0.5 Nm（-2）; n = 4）沿着动脉。总之，这些结果表明，剪切应力不是决定血管口径的唯一因素。我们认为，小动脉口径可能取决于剪切应力和局部压力分布之间的相互作用。
We tested the hypothesis that under physiological conditions, arterioles match their diameter to the level of shear stress. Haemodynamic and anatomical data were obtained in segments of the first-order arteriole of the rat cremaster muscle. Along this segment of similar to10 mm in length, local blood pressure decreased from 68 +/- 4 mmHg upstream to 54 +/- 3 mmHg downstream (n = 5). Pulse pressure decreased from 8.2 +/- 1.3 mmHg upstream to 4.1 +/- 0.6 mmHg downstream. At the same locations, an increase in arteriolar diameter was measured in vivo, from 179 +/- 4 muM upstream to 203 +/- 4 muM downstream (n = 10). In vitro pressure-diameter relations of maximally dilated vessels showed that the, passive diameter was larger in downstream than upstream segments over a 15-125 mmHg pressure range (n = 18). The wall stress was similar for the upstream vs. downstream location: 266 +/- 16 vs. 260 +/- 14 mN mm(-2). However, shear stress decreased from 30 +/- 5 to 21 +/- 5 dyn cm(-2) (3.0 +/- 0.5 to 2.1 +/- 0.5 N m(-2); n = 4) along the artery. In conclusion, these results demonstrate that shear stress is not the only factor in determining vascular calibre. We suggest that arteriolar calibre may rather depend on an interplay between shear stress and the local pressure profile.