Seida M, Vass K, Tomida S, Wagner H G, Klatzo I
Laboratory of Neuropathology and Neuroantomical Sciences, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland 20892.
Neurol Res. 1989 Dec;11(4):205-12. doi: 10.1080/01616412.1989.11739894.
The potential for recovery of brain tissue subjected to ischaemia at a threshold level of injury was evaluated in cats subjected to 20 min middle cerebral artery occlusion. In addition to assessment of regional cerebral blood flow and water content, the permeability of the bloodbrain barrier and morphological changes detected by light microscopy were studied at various time intervals. Our observations revealed that although a similar reduction of blood flow during arterial occlusion was found both in the caudate nucleus and the cerebral cortex, the reactive hyperaemia was consistently higher in the caudate nucleus than in the cortex. After 24 h the caudate nucleus also revealed a significantly higher water content and increased vascular permeability than the cortex. Morphological observations at 24 h in areas affected by ischaemia showed widespread, marked ischaemic neuronal injury, whereas at 3 d there was, in addition, a vigorous proliferative reaction of vascular elements. Cats sacrificed at 14 d revealed a remarkably good preservation of neurons, both in the caudate nucleus and cortex which otherwise showed a few circumscribed, small, infarcts surrounded by normal nerve cells. Our study suggests that neurons injured at threshold level have a considerable capacity for recovery. Otherwise, with a similar degree of ischaemia, the caudate nucleus appears more prone to increased vascular permeability and oedema than the cerebral cortex.
在接受20分钟大脑中动脉闭塞的猫中，评估了在损伤阈值水平下遭受缺血的脑组织的恢复潜力。除了评估局部脑血流量和含水量外，还在不同时间间隔研究了血脑屏障的通透性以及通过光学显微镜检测到的形态学变化。我们的观察结果显示，尽管在尾状核和大脑皮层中都发现了动脉闭塞期间类似的血流量减少，但尾状核的反应性充血始终高于皮层。24小时后，尾状核的含水量也明显高于皮层，血管通透性增加。缺血区域24小时的形态学观察显示广泛、明显的缺血性神经元损伤，而在3天时，血管成分还有活跃的增殖反应。在14天时处死的猫显示，尾状核和皮层中的神经元保存得非常好，否则会出现一些由正常神经细胞包围的局限性小梗死灶。我们的研究表明，在阈值水平受伤的神经元具有相当大的恢复能力。否则，在缺血程度相似的情况下，尾状核似乎比大脑皮层更容易出现血管通透性增加和水肿。
