Evolution of acute focal cerebral ischaemia in rats observed by localized H-1 MRS, diffusion-weighted MRI, and electrophysiological monitoring
Evolution of acute focal cerebral ischaemia in rats observed by localized H-1 MRS, diffusion-weighted MRI, and electrophysiological monitoring
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DOI：
10.1002/nbm.1940080505
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发表时间：
1995-08-01
影响因子：
2.9
通讯作者：
Hossmann, KA
中科院分区：
文献类型：
--
作者：
Gyngell, ML;Busch, E;Hossmann, KA
11只大鼠永久性闭塞右侧大脑中动脉(MCA)造成局灶性脑缺血，模型改良后可在核磁共振波谱仪上进行动物原位操作。在连续监测脑电和细胞外DC电位的同时，用局部H-1MRS和弥散加权MRI观察缺血性脑损伤的发展和所致的脑梗塞持续6h。脑缺血区在弥散加权图像上显示为高信号区。在大脑中动脉闭塞后的H-1谱中可以看到乳酸的信号，这表明开始了厌氧糖酵解。所有动物在闭塞后N-乙酰天冬氨酸都被耗尽。观察到一过性或阶段性乳酸升高与电生理检测到的自发性短暂性梗死区周围去极化事件一致。弥散加权图像显示的缺血区扩张也伴随着梗死灶周围的去极化。这些观察结果与短暂性梗死灶周围除极在梗死灶的生长过程中起作用是一致的。
Focal cerebral ischaemia was produced in 11 rats by permanent occlusion of the right middle cerebral artery (MCA) using a suture model modified to enable manipulation with the animals in situ in an NMR spectrometer. The development of the ischaemic insults and the resultant infarcts were observed for up to 6 h by localized H-1 MRS and diffusion-weighted MRI while performing continuous monitoring of electroencephalogram and extracellular DC potential. The ischaemic areas were depicted as regions of hyperintensity in the diffusion-weighted images. Signals due to lactate became visible in the H-1 spectra after MCA occlusion indicating the onset of anaerobic glycolysis. A depletion of N-acetylaspartate was seen in all animals post-occlusion. Transient or stepwise increases of lactate were observed to occur coincidentally with the events of spontaneous transient peri-infarct depolarization detected by the electrophysiological measurements. Expansion of the ischaemic area delineated in the diffusion-weighted images also accompanied peri-infarct depolarizations. These observations are consistent with transient peri-infarct depolarization playing a role in the growth of infarcts.