Stergiopulos N, Porret C A, De Brouwer S, Meister J J
Biomedical Engineering Laboratory, Swiss Federal Institute of Technology, Lausanne, Switzerland.
Am J Physiol. 1998 Jun;274(6):H1858-64. doi: 10.1152/ajpheart.1998.274.6.H1858.
Vasomotion has been studied on segments of rat mesenteric and femoral arteries perfused in vitro. We have investigated 1) the effect of perfusion flow on the characteristics of vasomotion and 2) the nature and patterns of vasomotion. We have found that perfusion flow is not a control parameter that contributes to the genesis of vasomotion but that it affects, in most cases only slightly, the frequency and amplitude of vasomotion. We have found evidence that vasomotion is low-dimensional chaotic. The correlation dimension ranged between 2 and 4, and the average Lyapunov's coefficient was approximately 0.1. A great variety of vasomotion patterns was observed with features that are typical of nonlinear deterministic systems: regular and irregular vasomotion, quasiperiodicity, period doubling and higher-order periods, intermittency, mixed modes, and bursting activity. Vasomotion patterns appeared occasionally to be highly sensitive to perturbations in perfusion flow, which also supported the existence of nonlinear dynamics. Finally, entrainment (phase locking) was observed when arteries were perfused with oscillatory flow with frequency in the neighborhood of the frequency of vasomotion.
已在体外灌注的大鼠肠系膜动脉和股动脉节段上研究了血管运动。我们研究了：1）灌注流量对血管运动特征的影响；2）血管运动的性质和模式。我们发现，灌注流量不是促成血管运动发生的控制参数，但在大多数情况下，它仅对血管运动的频率和幅度有轻微影响。我们已找到证据表明血管运动是低维混沌的。关联维数在2到4之间，平均李雅普诺夫系数约为0.1。观察到了各种各样的血管运动模式，这些模式具有非线性确定性系统的典型特征：规则和不规则的血管运动、准周期性、倍周期及高阶周期、间歇性、混合模式和爆发活动。血管运动模式偶尔似乎对灌注流量的扰动高度敏感，这也支持了非线性动力学的存在。最后，当用频率接近血管运动频率的振荡流灌注动脉时，观察到了同步（锁相）现象。
