Longitudinal MRI studies in the isoflurane-anesthetized rat: long-term effects of a short hypoxic episode on regulation of cerebral blood flow as assessed by pulsed arterial spin labelling.
Longitudinal MRI studies in the isoflurane-anesthetized rat: long-term effects of a short hypoxic episode on regulation of cerebral blood flow as assessed by pulsed arterial spin labelling.
复制标题
异氟烷麻醉大鼠的纵向 MRI 研究：通过脉冲动脉自旋标记评估短暂缺氧事件对脑血流调节的长期影响。
DOI：
10.1002/nbm.1243
复制
发表时间：
2008
影响因子：
2.9
通讯作者：
Wong,EricC
中科院分区：
文献类型：
--
作者：
Wegener,Susanne;Wong,EricC
MRI是纵向测量脑血流量（CBF）的有力工具。然而，大多数动物研究需要麻醉，这可能会干扰正常的生理机能。本研究使用异氟醚麻醉来研究大鼠重复扫描时脑血流的调节。使用FAIR（血流敏感交替倒置恢复）动脉自旋标记获得MR灌注图像，并计算绝对CBF。监测CBF在低氧（12% O2）和高碳酸（5% CO2）气体刺激下的变化。与基线相比，高碳酸血症导致CBF显著增加（195.5±21.5 vs 123.6±17.9 ml/ 100g /min），缺氧导致平均CBF值较小的非显著增加（145.4±13.4 ml/ 100g /min）。引人注目的是，当5天后重复测量时，与第一次成像相比，缺氧时CBF显著减少（93.2±8.1 ml/100 g/min）。在第一次MRI时不使用低氧和高碳酸气体，第二次MRI时基线CBF和CBF对缺氧反应的变化与幼稚大鼠相似。血气分析显示，与第一麻醉相比，第二麻醉期间动脉氧合略有减少。这些发现表明，在异氟醚麻醉的大鼠中，即使是短暂的缺氧发作也会对脑血管调节产生持久的影响。版权所有©2008 John Wiley & Sons， Ltd
MRI is a powerful tool for measuring cerebral blood flow (CBF) longitudinally. However, most animal studies require anesthesia, potentially interfering with normal physiology. Isoflurane anesthesia was used here to study CBF regulation during repetitive scanning in rats. MR perfusion images were acquired using FAIR (flow‐sensitive alternating inversion recovery) arterial spin labeling, and absolute CBF was calculated. CBF changes in response to a hypoxic (12% O2) and hypercapnic (5% CO2) gas stimulus were monitored. Hypercapnia led to a robust increase in CBF compared with baseline (195.5 ± 21.5 vs 123.6 ± 17.9 ml/100 g/min), and hypoxia caused a smaller non‐significant increase in mean CBF values (145.4 ± 13.4 ml/100 g/min). Strikingly, when measurements were repeated 5 days later, CBF was dramatically reduced in hypoxia (93.2 ± 8.1 ml/100 g/min) compared with the first imaging session. Without application of the hypoxic and hypercapnic gases during the first MRI, baseline CBF and CBF changes in response to hypoxia at the second MRI were similar to naive rats. Blood gas analyses revealed a slight reduction in arterial oxygenation during the second period of anesthesia compared with the first. These findings indicate that, in isoflurane‐anesthetized rats, even a short hypoxic episode can have long‐lasting effects on cerebrovascular regulation. Copyright © 2008 John Wiley & Sons, Ltd.