摘要
在以往系列实验研究初步阐明头部重点低温具有多方面有利于脑复苏的生化机理的基础上，本文试图从细胞形态学方面予以佐证。应用新西兰白兔３２只，４只为正常对照（Ⅰ组），其余均用改良“四血管法”造成脑缺血（３０ｍｉｎ）模型，分为缺血对照（Ⅱ组）、常温再灌注（Ⅲ组）和头部重点低温（２８±０．５℃）再灌注（Ⅳ组）三组，Ⅲ、Ⅳ组再分为再灌注３０、１８０和３６０ｍｉｎ三亚组，每组各４只。处死后在体灌注固定液固定脑组织，将全脑作冠状切片制成常规石腊切片。采用计算机图像分析技术，将脑组织１２个部位的神经元按预定标准判为Ａ（正常）、Ｂ（轻伤）、Ｃ（重伤）和Ｄ（坏死）四类，予以分别计数和算出所占百分比。结果：Ⅱ组与Ⅰ组相比，Ａ类神经元所占百分比明显减少，Ｂ、Ｃ、Ｄ类明显增多；Ⅲ组Ａ、Ｂ类神经元进一步减少，而Ｃ、Ｄ类更显著增多；Ⅳ组Ａ、Ｂ类神经元所占百分比显著高于Ⅲ组，Ｄ类则明显减少，随着时间从３０～３６０ｍｉｎ，Ｃ、Ｄ类所占百分比基本恒定。结论：头部重点低温（脑温２８℃上下）对缺血后再灌注损伤具有明显的抑制作用，正常神经元得以免于受损。随着低温时间适当延长，轻伤神经元可能获救，而重伤和坏死神经元则无复苏可能。
Our previous experimental studies have demonstrated that selective head cooling had multifaceted beneficial effects on brain resuscitation.It is was worthwhile to explore further the histomor phological evidences in relation to it.32 Newzealand rabbits were allocated into group Ⅰ(normal control),group Ⅱ(simply global ischemia), group Ⅲ(postischemic normothermic reperfusion), and group Ⅳ(reperfusion with selective head cooling, to lower the brain temperature to 28±0 5℃ by means of “ice cap”),latter two groups were further divided, according to the duration of reperfusion for 30,180,and 360 min, into 1,2 and 3 subgroups, with 4 rabbits in each. Global ischemia was accomplished by modified “4 vessel mode” and lasted for 30min. As all requirements were fulfilled, rabbits were sacrificed. Brains were fixed in situ, and taken out for coronary sections, which were stained and treated as routine. Slides were sent for computerized image analysis. Neurons of 12 regions were differentiated respectively into type A(normal), type B(mildly damaged), type C(severely damaged)and type D(necrotic).Each neuron type was counted and calculated into percentage. Results: As compared with group Ⅰ,in group Ⅱ, the percentage of type A neuron was markedly decreased, while that of type B,C,D neurons increased significantly. In group Ⅲ, type A and B neurons decreased further, while type C and D neurons markedly increased. In contrast, in group Ⅳ the percentage of type A and B neurons was markedly higher, while type D neuron significantly lower, as compared with group Ⅲ. As the duration of reperfusion prolonged up to 360min, the percentage of type C,D neurons remained relatively unchanged. Conclusions:Selective head cooling has marked inhibitory effects on reperfusion damage in cerebral ischemia, thus, the normal neurons will be saved. As duration of hypothermia prolonged appropriately, slightly damaged neurons may be salvagable, but severely damaged and necrotic neurons not.
出处
《临床麻醉学杂志》
CAS
CSCD
北大核心
1996年第6期293-296,共4页
Journal of Clinical Anesthesiology
基金
全军"八五科研规划"重点课题
关键词
头部重点低温
脑复苏
细胞形态学
计算机
Selective head cooling Brain resuscitation Histomorphology Computer
