血管弯曲程度对内源性一氧化氮分布的影响

The Effect of Different Curvature on the Distribution of Nitric Oxide Concentration in the Curved Arterial Segment

一氧化氮(NO)在血流调控中起着重要作用,目前关于血管弯曲程度对NO分布的影响尚不明确。建立11个不同弯曲程度的几何模型,利用多物理场耦合建模仿真的方法,对内源性NO在血液、血管壁及周围组织中的浓度分布进行数值模拟。数值结果表明,在血管弯曲处,NO径向分布不均,内外侧浓度存在差异,且随着弯曲程度的增加,浓度差值呈先上升后缓慢降低的趋势。在血管投影长度为定值20 mm的情况下,当弯曲高度取2 mm、对应曲率为0.04时,NO在内外侧平滑肌区域的浓度差值达到最大,外侧边界比内侧高23.74%。研究揭示弯曲程度对内源性NO分布的影响,所产生的NO浓度分布差异可能是导致血管形态变化以及血管病变的重要因素,为进一步探究发病机理以及患病风险评估提供一定的理论依据。

Nitric oxide （NO） produced by the endothelium plays an important role in regulating vascular tone. However, the effect of different curvature on the distribution of NO concentration in the curved arterial segment has not been clear. We developed eleven mass transport models with different curvature to simulate the distributions for NO in blood, vascular walls and surrounding tissue. Results showed that the radical distribution of NO was uneven in the curved segment. The outer concentration was higher than the inner one. And the concentration difference increased and then decreased with the increased curvature. In the smooth muscle region, the concentration difference reached the maximum when the curved height was increased to 2ram under the condition of the vessel projection length was a constant （20 mm） ,where the curvature was increased to 0.04, the outer boundary concentration was 23.74% higher than the inner one. This study revealed the effect of different curvature on NO concentration, and suggested that the uneven distribution of NO might cause vascular morphology changes and lead to vascular disease. Those models may provide a theoretical support for the further research and vascular disease risk assessment.