Geng Jin-Xia, Zhang Min, Li Wen-Bin, Guo Li-Hua, Li Qing-Jun, Xian Xiao-Hui
Department of Pathophysiology, Hebei Medical University, Shijiazhuang 050017, China.
Zhongguo Ying Yong Sheng Li Xue Za Zhi. 2007 Feb;23(1):24-9.
To study the effect of different intervals between occlusions of vertebral arteries and bilateral common carotid arteries on the Pulsinelli 4-vessel occlusion global cerebral ischemic model, and the features of ischemia of the brainstem and hippocampus induced by occulusion of bilateral common carotid arteries under the condition of occlusion of unilateral vertebral artery.
Eighty four adult male Wistar rats were divided into 4 groups randomly: control group, bilateral vertebral artery occluding group, global brain ischemic insult group, and unilateral vertebral artery occluding plus bilateral common carotid arteries occluding group. In the global brain ischemic insult group, rats were further divided into 24 h, 48 h, and 72 h interval subgroups according to the interval between the occlusion of the vertebral arteries and bilateral common carotid arteries. The responses including enlarging of pupils and the light reflex during the brain ischemia were observed. The duration of right reflex disappearing, the general state, and the delayed neuronal death (DND) of pyramidal neurons in the CA1 hippocampus of the rats after the brain ischemia were also observed.
Among the global brain ischemic insult group, both the responses and DND were more severe in 72 h interval subgroup than those in 24 h and 48 h interval subgroups. There was no significant difference between 24 h and 48 h interval subgroups. When the bilateral common carotid arteries were occluded under the condition of occlusion of unilateral vertebral artery, severe DND was observed in the CA1 hippocampus ipsilateral to the occluding vertebral artery, but no significant DND was observed in the contralateral CA1 hippocampus.
The results suggested that the prior occlusion of the bilateral vertebral arteries during producing Pulsinelli 4-vessel occlusion global cerebral ischemic model might be a cerebral ischemic preconditioning that could protect to some extent pyramidal neurons of the hippocampus against severe ischemic insult induced by occlusion of bilateral common carotid arteries within 48 h. Moreover, There is ipsilateral predominance of blood perfusion from one side of vertebral artery to the brainstem and hippocampus, although there was Willis artery circle in rats.
研究椎动脉与双侧颈总动脉阻断间隔时间对Pulsinelli四血管闭塞全脑缺血模型的影响，以及在单侧椎动脉闭塞情况下双侧颈总动脉闭塞所致脑干和海马缺血的特征。
将84只成年雄性Wistar大鼠随机分为4组：对照组、双侧椎动脉闭塞组、全脑缺血损伤组和单侧椎动脉闭塞加双侧颈总动脉闭塞组。在全脑缺血损伤组中，根据椎动脉与双侧颈总动脉阻断的间隔时间，将大鼠进一步分为24小时、48小时和72小时间隔亚组。观察脑缺血期间瞳孔扩大和光反射等反应。还观察了脑缺血后大鼠右侧反射消失的持续时间、一般状态以及海马CA1区锥体细胞的迟发性神经元死亡（DND）情况。
在全脑缺血损伤组中，72小时间隔亚组的反应和DND均比24小时和48小时间隔亚组更严重。24小时和48小时间隔亚组之间无显著差异。当在单侧椎动脉闭塞的情况下双侧颈总动脉闭塞时，在闭塞椎动脉同侧的海马CA1区观察到严重的DND，但在对侧海马CA1区未观察到明显的DND。
结果表明，在制作Pulsinelli四血管闭塞全脑缺血模型时先行双侧椎动脉闭塞可能是一种脑缺血预处理，可在一定程度上保护海马锥体细胞免受48小时内双侧颈总动脉闭塞所致的严重缺血损伤。此外，尽管大鼠存在Willis动脉环，但椎动脉一侧对脑干和海马的血液灌注存在同侧优势。
