Evaluation of cerebrovascular impedance and wave reflection in mouse by ultrasound.
Evaluation of cerebrovascular impedance and wave reflection in mouse by ultrasound.
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DOI：
10.1038/jcbfm.2014.229
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发表时间：
2015-03
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影响因子：
--
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中科院分区：
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--
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遗传和手术小鼠模型通常用于研究脑血管疾病，但它们的大小使得侵入性血流动力学测试在技术上具有挑战性。本研究的目的是证明一种无创测量脑血管阻抗和波反射在小鼠使用高频超声在左颈总动脉（LCCA），并检查是否与高碳酸血症相关的微血管变化可以检测到这样的方法。使用高频超声系统（40 MHz）研究了10只小鼠（C57 BL/6 J）。从LCCA获得管腔面积和血流波形，并用于计算正常碳酸和高碳酸（5%CO2）通气下的脉搏波速度、输入阻抗、反射幅度和渡越时间。在高碳酸血症时，观察到血管阻力降低87%± 12%。虽然输入阻抗的模量在高碳酸血症时没有变化，但在低谐波下观察到指示总动脉顺应性增加的相位降低，以及时域（0.57±0.08 vs 0.68±0.08，P=0.04）和频域（0.62±0.08 vs 0.73±0.06，P=0.02）反射系数增加。有趣的是，发现大部分LCCA血流进入颈内动脉（范围=76%至90%，N=3），表明该血管中的血液动力学测量是小鼠脑内反应性的良好指标。
Genetic and surgical mouse models are commonly used to study cerebrovascular disease, but their size makes invasive hemodynamic testing technically challenging. The purpose of this study was to demonstrate a noninvasive measurement of cerebrovascular impedance and wave reflection in mice using high-frequency ultrasound in the left common carotid artery (LCCA), and to examine whether microvascular changes associated with hypercapnia could be detected with such an approach. Ten mice (C57BL/6J) were studied using a high-frequency ultrasound system (40 MHz). Lumen area and blood flow waveforms were obtained from the LCCA and used to calculate pulse-wave velocity, input impedance, and reflection amplitude and transit time under both normocapnic and hypercapnic (5% CO2) ventilation. With hypercapnia, vascular resistance was observed to decrease by 87%±12%. Although the modulus of input impedance was unchanged with hypercapnia, a phase decrease indicative of increased total arterial compliance was observed at low harmonics together with an increased reflection coefficient in both the time (0.57±0.08 versus 0.68±0.08, P=0.04) and frequency domains (0.62±0.08 versus 0.73±0.06, P=0.02). Interestingly, the majority of LCCA blood flow was found to pass into the internal carotid artery (range=76% to 90%, N=3), suggesting that hemodynamic measurements in this vessel are a good metric for intracerebral reactivity in mouse.
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影响因子：
9.6
作者：
Huez, S;Brimioulle, S;Vachiéry, JL
通讯作者：
Vachiéry, JL
影响因子：
2.9
作者：
Reddy, AK;Taffet, GE;Hartley, CJ
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Hartley, CJ
影响因子：
3.3
作者：
Barbier, EL;Silva, AC;Koretsky, AP
通讯作者：
Koretsky, AP
影响因子：
3.3
作者：
Howles, Gabriel P.;Ghaghada, Ketan B.;Qi, Yi;Mukundan, Srinivasan, Jr.;Johnson, G. Allan
通讯作者：
Johnson, G. Allan
影响因子：
4.4
作者：
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通讯作者：
Crawley, Adrian P.