Antonova Mariya L, Antonov Pavel S, Marinov Georgi R, Vlaskovska Mila V, Kasakov Lubomir N
Institute of Neurobiology, Bulgarian Academy of Sciences, Acad. G. Bonchev Str., bl. 23, 1113 Sofia, Bulgaria.
Ann Biomed Eng. 2008 Jun;36(6):947-57. doi: 10.1007/s10439-008-9477-0. Epub 2008 Mar 11.
The arterial wall viscoelasticity plays an essential role in the vascular responsiveness to vasoactive drugs or pathologies. The aim of this investigation was to derive and compare resonance curve (RC), natural frequency (f(0)), dynamic modulus of elasticity (E'), and coefficient of viscosity (beta) of (i) vital and devitalized preparations of rat thoracic and abdominal aorta, (ii) human arterial prostheses, and to study the histomorphology of vital and devitalized rat aorta. The method of low frequency forced oscillations was employed. RC of vital preparations showed a hardening type of elasticity whereas in devitalized preparations it was of softening type. E' increased nonlinearly, f(0) decreased and beta increased linearly with equivalent intraluminal pressure (p(eqi)). Distensibility of abdominal aorta was lower than thoracic aorta. Distensibility decreased with increasing p(eqi). E', f(0), and beta increased significantly after devitalization. It was suggested that postmortem viscoelastic characteristics should not be used directly to specify the vital arteries viscoelasticity. RC of human prostheses showed a softening type of elasticity. Arterial prostheses have low circumferential distensibility with E'-values higher than reported in the literature for human arteries. The method of forced oscillations could be employed for studying the arterial wall biomechanics and viscoelasticity of arterial prostheses.
动脉壁粘弹性在血管对血管活性药物或病变的反应中起着至关重要的作用。本研究的目的是推导并比较（i）大鼠胸主动脉和腹主动脉的活体和失活标本、（ii）人体动脉假体的共振曲线（RC）、固有频率（f(0)）、动态弹性模量（E'）和粘度系数（β），并研究活体和失活大鼠主动脉的组织形态学。采用低频强迫振荡法。活体标本的RC显示出硬化型弹性，而在失活标本中则为软化型。E'随等效腔内压力（p(eqi)）非线性增加，f(0)降低，β线性增加。腹主动脉的扩张性低于胸主动脉。扩张性随p(eqi)增加而降低。失活后E'、f(0)和β显著增加。有人认为，死后的粘弹性特征不应直接用于确定活体动脉的粘弹性。人体假体的RC显示出软化型弹性。动脉假体的周向扩张性较低，E'值高于文献报道的人体动脉值。强迫振荡法可用于研究动脉壁生物力学和动脉假体的粘弹性。
