Nagasawa H, Kogure K
Department of Neurology, Tohoku University, School of Medicine, Sendai, Japan.
Stroke. 1989 Aug;20(8):1037-43. doi: 10.1161/01.str.20.8.1037.
We describe a new focal ischemia model consisting of unilateral middle cerebral artery occlusion with a silicone rubber cylinder attached to a nylon surgical thread inserted through the internal carotid artery in rats. Recirculation was accomplished by pulling the thread out of the artery. We evaluated the reliability of this model and studied the influence of reperfusion of the brain by measuring regional cerebral blood flow in 30 rats and by using conventional neuropathologic methods after different periods of occlusion in 48 rats. The anterior neocortex and the lateral part of the caudate putamen, which were supplied by the occluded middle cerebral artery, were the regions most frequently damaged. After 1 hour of occlusion in five rats, in the cortex supplied by the occluded artery mean +/- SD blood flow was 0.19 +/- 0.08 ml/g/min (approximately 15% of that in the corresponding region of five sham-operated control rats), and mild scattered ischemic cell change was observed. Three (n = 5) or six (n = 5) hours of occlusion reduced blood flow more severely and caused severe ischemic cell changes in the cortex supplied by the occluded artery in proportion to the duration of ischemia. Characteristically, in five rats subjected to 3 hours of occlusion followed by 3 hours of recirculation, blood flow was restored and spongy edematous change was observed in the cortex supplied by the recirculated artery. This change resulted in hypoperfusion of the neighboring cortical region surrounding the recirculated area. Our model should be useful in various investigations of the influence of reperfusion on focal ischemic brain injury.
我们描述了一种新的局灶性缺血模型，该模型通过将硅胶橡胶柱附着于一根插入大鼠颈内动脉的尼龙手术线来实现大脑中动脉单侧闭塞。通过将线从动脉中抽出实现再灌注。我们评估了该模型的可靠性，并通过测量30只大鼠的局部脑血流量以及在48只大鼠不同闭塞时间段后使用传统神经病理学方法，研究了脑再灌注的影响。由闭塞的大脑中动脉供血的前新皮质和尾状壳核外侧部分是最常受损的区域。在5只大鼠闭塞1小时后，在闭塞动脉供血的皮质中，平均±标准差血流量为0.19±0.08 ml/g/min（约为5只假手术对照大鼠相应区域血流量的15%），并观察到轻度散在的缺血性细胞改变。闭塞3（n = 5）或6（n = 5）小时更严重地降低了血流量，并在闭塞动脉供血的皮质中根据缺血持续时间导致了严重的缺血性细胞改变。典型的是，在5只经历3小时闭塞随后3小时再灌注的大鼠中，血流量恢复，且在再灌注动脉供血的皮质中观察到海绵状水肿改变。这种改变导致了再灌注区域周围邻近皮质区域的灌注不足。我们的模型在各种关于再灌注对局灶性缺血性脑损伤影响的研究中应会很有用。
