脑血流低灌注老龄大鼠中脑皮质血流的改变与血清总胆固醇和高密度脂蛋白的动态变化

Dynamic changes of cortical blood flow and serum total cholesterol and high density lipoprotein in brains of aging rat during cerebral hypoperfusion

摘要:

目的：通过建立脑血流低灌注模型，观察老龄大鼠脑血流的变化以及在脑血流低灌注下血清中总胆固醇（Total cholesterol，TC）和高密度脂蛋白（High density lipoprotein，HDL）的动态变化。方法：采用持久性双侧颈总动脉结扎法（2VO）致老龄大鼠脑血流灌注不足，测定术后7、14、21、28 d大鼠脑皮质血流；检测、比较术后不同时间段大鼠血清中 TC 和 HDL 浓度差异。结果：术后第14天大鼠脑颞区血流出现明显减少；术后 21、28 d大鼠脑局部皮质血管有再生侧支形成，大鼠脑颞区血流仍未恢复；术后第 14天血清中 HDL、TC 含量明显高于假手术组（P＜0.05），随着缺血时间延长，又逐渐降低。结论：血清 TC 和 HDL 浓度在脑缺血灌注不足的不同时间段经历了先增强后减弱的动态变化，提示脑血流低灌注老龄大鼠因大脑血流灌注不足可出现体内胆固醇代谢失衡并出现应激调节现象。

Abstract:

Objective：To investigate the change of cortical blood flow and the dynamic changes of serum total cholesterol（TC） and high density lipoprotein（HDL） in brains of aging rat during cerebral ischemic injury. Methods：The model of aging rats with cerebral hypoperfusion was successfully constructed by persistent bilateral common carotid artery ligation（2VO）. The cortical blood flow and the concentration of serum TC and HDL at different time points were determined and compared. Results：Compared with the sham-operated group，the temporal blood flow was significantly decreased in 14 d group. But the collateral vessels were gradually regenerated and formed in local brain，while the temporal blood flow was restored in 21 d and 28 d group. The concentration of HDL and TC was significantly higher in 14 d group than in the sham-operated group（P<0.05），and both of them were decreased with the extention of ischemia time. Conclusions：The serum TC and HDL concentration undergo dynamic changes-increasing first and then decreasing during the process of cerebral hypoperfusion，which suggests that aging rats of cerebral hypoperfusion have unbalanced metabolism and display stress regulatory phenomenon due to cerebral hypoperfusion.