Zhang Hong, Li Li, Xu Guo-Ying, Mei Yuan-Wu, Zhang Jun-Jian, Murong Shen-Xing, Sun Sheng-Gang, Tong E-Tang
Department of Neurology, Zhongnan Hospital of Wuhan University, Wuhan, 430071, China.
Department of Neurology, the First Affiliated Hospital of Fujian Medical University, Fuzhou, 350005, China.
J Huazhong Univ Sci Technolog Med Sci. 2014 Jun;34(3):354-358. doi: 10.1007/s11596-014-1282-4. Epub 2014 Jun 18.
Under global cerebral ischemia, the effect of different brain temperature on cerebral ischemic injury was studied. Male Sprague-Dawley rats were divided into normothermic (37-38°C) ischemia, mild hypothermic (31-32°C) ischemia, hyperthermic (41-42°C) ischemia and sham-operated groups. Global cerebral ischemia was established using the Pulsinelli four-vessel occlusion model and brain temperature was maintained at defined level for 60 min after 20-min ischemia. The expression of c-fos protein and the levels of malondialdehyde (MDA) and lactate in brain regions were detected by immunochemistry and spectrophotometrical methods, respectively. C-fos positive neurons were found in the hippocampus and cerebral cortex after cerebral ischemia reperfusion. Mild hypothermia increased the expression of c-fos protein in both areas, whereas hyperthermia decreased the expression of c-fos protein in the hippocampus at 24 h reperfusion, and the cerebral cortex at 48 h reperfusion when compared to normothermic conditions. In normothermic, mild hypothermic and hyperthermic ischemia groups, the levels of MDA and lactate in brain tissue were increased at 24, 48 and 72 h reperfusion following 20-min ischemia as compared with the sham-operated group (P<0.01). The levels of MDA and lactate in mild hypothermic group were significantly lower than those in normothermic group (P<0.01). It is suggested that brain temperature influences the translation of the immunoreactive protein product of c-fos after global cerebral ischemia, and MDA and lactate are also affected by hypothermia and hyperthermia.
在全脑缺血情况下，研究了不同脑温对脑缺血损伤的影响。将雄性Sprague-Dawley大鼠分为正常体温（37 - 38°C）缺血组、轻度低温（31 - 32°C）缺血组、高温（41 - 42°C）缺血组和假手术组。采用Pulsinelli四血管闭塞模型建立全脑缺血模型，在缺血20分钟后将脑温维持在设定水平60分钟。分别通过免疫化学和分光光度法检测脑区中c-fos蛋白的表达以及丙二醛（MDA）和乳酸的水平。脑缺血再灌注后，在海马体和大脑皮层中发现了c-fos阳性神经元。与正常体温情况相比，轻度低温增加了这两个区域c-fos蛋白的表达，而高温在再灌注24小时时降低了海马体中c-fos蛋白的表达，在再灌注48小时时降低了大脑皮层中c-fos蛋白的表达。在正常体温、轻度低温和高温缺血组中，与假手术组相比，缺血20分钟后再灌注24、48和72小时时脑组织中MDA和乳酸水平升高（P<0.01）。轻度低温组中MDA和乳酸水平显著低于正常体温组（P<0.01）。提示脑温影响全脑缺血后c-fos免疫反应性蛋白产物的翻译，且MDA和乳酸也受低温和高温影响。
