Nicotine Affects Murine Aortic Stiffness and Fatigue Response During Supraphysiological Cycling.
Nicotine Affects Murine Aortic Stiffness and Fatigue Response During Supraphysiological Cycling.
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尼古丁影响超生理循环过程中小鼠主动脉僵硬和疲劳反应。
DOI：
10.1115/1.4051706
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发表时间：
2022
期刊：
影响因子：
--
通讯作者：
Lee,Sang-JoonJohn
中科院分区：
文献类型：
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作者：
Ho,Elizabeth;Mulorz,Joscha;Wong,Jason;Wagenhäuser,MarkusU;Tsao,PhilipS;Ramasubramanian,AnandK;Lee,Sang-JoonJohn
尼古丁暴露是几种心血管疾病的主要危险因素。虽然尼古丁对主动脉重塑过程的有害影响已在一定程度上进行了研究，但其生物物理后果尚未完全阐明。在这项研究中，我们应用准静态和动态载荷来量化暴露于尼古丁影响小鼠动脉组织机械行为的方式。对暴露于25 mg/kg/天皮下尼古丁28天的C57 BL/6小鼠的胸主动脉节段进行开放周向配置的单轴拉伸载荷。将尼古丁处理小鼠的主动脉节段与相同数量的对照小鼠的主动脉节段进行比较，在50%应变下，周向方向的刚度几乎高出两倍（377 kPa ± 165 kPa vs 191 kPa ± 65 kPa，n = 5，p = 0.03）。在超生理负荷下，使用退化幂律拟合疲劳数据，我们观察到尼古丁处理的椎骨表现出比对照椎骨显著更高的峰值应力、更大的张力损失和更宽的振荡带（所有三个变量的p ≤ 0.01）。与简单的应力松弛测试相比，疲劳循环被证明是更敏感和灵活的辨别尼古丁引起的机械行为的变化在许多周期。因此，超生理疲劳循环可能具有更广泛的潜力，以揭示由其他外源性毒素或病理条件引起的血管力学的细微变化
Nicotine exposure is a major risk factor for several cardiovascular diseases. Although the deleterious effects of nicotine on aortic remodeling processes have been studied to some extent, the biophysical consequences are not fully elucidated. In this investigation, we applied quasi-static and dynamic loading to quantify ways in which exposure to nicotine affects the mechanical behavior of murine arterial tissue. Segments of thoracic aortas from C57BL/6 mice exposed to 25 mg/kg/day of subcutaneous nicotine for 28 days were subjected to uniaxial tensile loading in an open-circumferential configuration. Comparing aorta segments from nicotine-treated mice relative to an equal number of control counterparts, stiffness in the circumferential direction was nearly twofold higher (377 kPa ± 165 kPa versus 191 kPa ± 65 kPa, n = 5, p = 0.03) at 50% strain. Using a degradative power-law fit to fatigue data at supraphysiological loading, we observed that nicotine-treated aortas exhibited significantly higher peak stress, greater loss of tension, and wider oscillation band than control aortas (p ≤ 0.01 for all three variables). Compared to simple stress relaxation tests, fatigue cycling is shown to be more sensitive and versatile in discerning nicotine-induced changes in mechanical behavior over many cycles. Supraphysiological fatigue cycling thus may have broader potential to reveal subtle changes in vascular mechanics caused by other exogenous toxins or pathological conditions