Department of Neurosurgery, JCHO Tokyo Kamata Medical Center.
Department of Internal Medicine, Toho University Sakura Medical Center.
J Atheroscler Thromb. 2021 Nov 1;28(11):1241-1249. doi: 10.5551/jat.59451. Epub 2021 Jan 20.
Stroke is well known to lead to hypertension; nevertheless, the role of vascular function in hypertension remains unclear. In this study, we aimed to clarify the mechanism underlying increased arterial stiffness following stroke.
The cardio-ankle vascular index (CAVI) was measured in five New Zealand White rabbits. Under general anesthesia, intracranial pressure (ICP) was increased by injecting saline (15 mL) into the cisterna magna. ICP was monitored using a catheter inserted into the subarachnoid space via right frontal bone craniotomy. Blood pressure (BP), CAVI, and common carotid flow (CCF) were evaluated, and the responses of these parameters to increased ICP were analyzed.
Saline injection into the cisterna magna increased the ICP by over 20 mmHg. Both BP and CAVI increased from 63.2±4.84 to 128.8±14.68 mmHg and from 4.02±0.28 to 4.9±0.53, respectively. Similarly, BP and CCF increased. When hexamethonium was administered before the increase in ICP, the increase in BP (132.2±9.41 mmHg with 10 mg/kg hexamethonium vs. 105.6±11.01 mmHg with 100 mg/kg hexamethonium) and CAVI (5.02±0.64 with 10 mg/kg hexamethonium vs. 4.82±0.42 with 100 mg/kg hexamethonium) were suppressed in a dose-dependent manner.
Increased ICP causes an increase in BP and CAVI, suggesting that enhanced stiffness of the muscular arteries contributes to high BP. Blocking the autonomic nervous system with hexamethonium suppresses the increase in BP and CAVI, indicating that these increases are mediated by activation of the autonomic nervous system.
众所周知，中风会导致高血压；然而，血管功能在高血压中的作用仍不清楚。在这项研究中，我们旨在阐明中风后动脉僵硬增加的机制。
在五只新西兰白兔中测量心踝血管指数（CAVI）。在全身麻醉下，通过右额骨开颅术将导管插入蛛网膜下腔，向小脑延髓池内注入生理盐水（15 mL）以升高颅内压（ICP）。通过插入蛛网膜下腔的导管监测 ICP。评估血压（BP）、CAVI 和颈总血流（CCF），并分析这些参数对升高 ICP 的反应。
向小脑延髓池内注入生理盐水使 ICP 升高超过 20 mmHg。BP 和 CAVI 分别从 63.2±4.84 mmHg 增加到 128.8±14.68 mmHg 和从 4.02±0.28 mmHg 增加到 4.9±0.53 mmHg。同样，BP 和 CCF 也增加了。当在 ICP 升高前给予六烃季铵时，BP（用 10 mg/kg 六烃季铵增加 132.2±9.41 mmHg，用 100 mg/kg 六烃季铵增加 105.6±11.01 mmHg）和 CAVI（用 10 mg/kg 六烃季铵增加 5.02±0.64 mmHg，用 100 mg/kg 六烃季铵增加 4.82±0.42 mmHg）的增加呈剂量依赖性抑制。
升高的 ICP 导致 BP 和 CAVI 增加，提示肌肉动脉僵硬增加导致高血压。用六烃季铵阻断自主神经系统抑制 BP 和 CAVI 的增加，表明这些增加是通过自主神经系统的激活介导的。
