激光散斑成像结合光化学脑缺血模型及在相关药物筛查中的应用

发布时间：2018-03-03 07:50

本文选题：激光散斑成像　切入点：脑血流　出处：《华中科技大学》2014年博士论文　论文类型：学位论文

【摘要】：目的：激光散斑成像是近年兴起的一种活体成像技术,用于观察活体组织内的血流,而如何运用于脑血管病的研究还存在医学转化的实际困难。本论文采用激光散斑成像技术观察小鼠脑血流量和脑血流改变情况下侧支循环情况,结合小鼠的光化学脑缺血模型和标准化方法用于动态、连续监测缺血灶模型的信号改变规律。进一步分析血流信号改变与脑组织病理变化相互关系,探索光化学模型的神经血管的变化规律。以验证光化学脑缺血模型激光散斑成像成为一种高效的药物筛查方法的可能性。方法：利用激光散斑成像系统观察C57/BL6小鼠的脑皮层血流图,通过结扎单侧颈动脉的方法观察小鼠侧支循环形成情况。通过不同激光剂量进行小鼠脑光化学造模,探索不同剂量激光造模的效果与特点。分析脑皮层缺血区域血流信号的改变与小鼠脑梗塞体积、小血管数量的关系。免疫荧光检测小血管的变化规律及以小血管为中心的神经细胞、胶质细胞的变化规律。采用激光散斑成像技术验证尤瑞克林、米诺环素、地塞米松的对光化学脑缺血模型的作用。结果：激光散斑成像实现C57小鼠动态的脑皮层血流检查,C57小鼠进行光化学脑缺血造模后可以进行多次重复性检查。不同剂量激光造模造成的光化学缺血灶病理改变具有不同特点。光化学缺血区域标准化的SrCBF (Standardized Regional Cerebral Blood Flow)与缺血组织体积呈负相关关系,相关系数R2为0.9001；标准化的SrCBF变化趋势与缺血区域小血管的单位面积百分比变化趋势类似。病理结果显示化学模型的缺血区域在1d内仍有Neun阳性细胞；28d发现在缺血边缘发现极少量的Neun阳性及Brdu阳性的细胞。通过GFAP染色,可以发现在光化学缺血性脑缺血模型的缺血灶的边缘区可以发现星形胶质细胞的活化,5d时星形细胞活化达到顶峰,活化的星形细胞与小血管关系密切。在光化学模型的药物筛查实验中,手术后3d收集比较小鼠皮层的兴趣区的SrCBF,米诺环素组的局部血流量和脑缺血组织体积与对照组比较具有统计学差异。结论：激光散斑成像系统能够实时动态的显示脑血流的变化,这为小鼠脑皮层小血管功能和脑缺血的侧支循环相关研究提供了良好的研究工具。不同剂量的光化学造模可以制作出不同程度的缺血梗塞灶,适合不同类型实验的研究需要。通过激光散斑成像的标准化的SrCBF可以作为血流量的指标,可用于评价不同小鼠的血流恢复程度,一定程度上反映小鼠的光化学缺血灶的缺血组织体积大小,提示局部小血管的数量。光化学脑缺血模型中,小血管与神经细胞、星形胶质细胞具有紧密关系。激光散斑成像系统光化学脑缺血模型检验脑缺血后的药物治疗效果具有一定可靠性和高效性,米诺环素等抗炎、血管保护药物可能有益于相关疾病的治疗。
[Abstract]:Objective: laser speckle imaging is a living imaging technique developed in recent years, which is used to observe the blood flow in living tissue. In this paper, we used laser speckle imaging technique to observe the cerebral blood flow and the change of cerebral blood flow in mice. In combination with the photochemical cerebral ischemia model of mice and the standardized method, the signal changes of the ischemic focal model were continuously monitored, and the relationship between the changes of blood flow signal and the pathological changes of brain tissue was further analyzed. In order to verify the possibility of laser speckle imaging of photochemical cerebral ischemia model as an effective drug screening method, the changes of nerve and blood vessels in photochemical model were investigated. Methods: the cerebral cortex blood flow of C57 / BL6 mice was observed by laser speckle imaging system. The formation of collateral circulation was observed by ligation of unilateral carotid artery. To explore the effects and characteristics of laser modeling with different doses, to analyze the changes of blood flow signal in cerebral ischemic region and the volume of cerebral infarction in mice. The relationship between the number of small blood vessels, the changes of small blood vessels by immunofluorescence, and the changes of nerve cells and glial cells with small vessels as the center. Eureklin and minocycline were verified by laser speckle imaging. Effect of dexamethasone on photochemical cerebral ischemia model. Results: dynamic cerebral cortical blood flow examination in C57 mice was achieved by laser speckle imaging. After photochemical cerebral ischemia model was made in C57 mice, repeated examinations could be carried out. Pathology of photochemical ischemic foci caused by laser modeling with different doses. The changes have different characteristics. There is a negative correlation between the volume of ischemic tissue and the standardized Regional Cerebral Blood flow in photochemical ischemic region. The correlation coefficient R2 was 0.9001; the change trend of standardized SrCBF was similar to that of the percentage change of unit area of small vessels in ischemic region. Pathological results showed that there were still Neun positive cells in ischemic region within 1 day and 28 days after ischemia. A very small number of Neun and Brdu positive cells were found on the edges. It can be found that the activation of astrocytes peaked at 5 days after photochemical ischemic cerebral ischemia in the marginal region of ischemic foci. Activated astrocytes are closely associated with small blood vessels. In the photochemical model of drug screening, Three days after operation, the SrCBF of cortical area of interest, the regional blood flow and the volume of cerebral ischemic tissue in minocycline group were compared with those in the control group. Conclusion: laser speckle imaging system can display the changes of cerebral blood flow in real time. This provides a good tool for the study of cortical microvascular function and collateral circulation of cerebral ischemia in mice. Different doses of photochemical models can be used to make different ischemic infarct areas. Standardized SrCBF by laser speckle imaging can be used as an index of blood flow and can be used to evaluate the degree of blood flow recovery in different mice. To some extent, it reflects the volume of ischemic tissue in mice with photochemical ischemia, indicating the number of local small vessels. In the model of photochemical cerebral ischemia, small vessels and nerve cells, There is a close relationship between astrocytes. The photochemical cerebral ischemia model of laser speckle imaging system has a certain reliability and high efficiency in detecting the effect of drug therapy after cerebral ischemia, such as minocycline, etc. Vascular protection drugs may be beneficial to the treatment of related diseases.
【学位授予单位】：华中科技大学
【学位级别】：博士
【学位授予年份】：2014
【分类号】：R743.3

【共引文献】