大鼠心脏骤停后脑损伤与葡萄糖代胡拱系的实验研究

Study of the relationship between brain injury and glucose metabolism in rat model of cardiac arrest

目的 明确心脏骤停（cardiac arrest, CA）后脑损伤程度与脑葡萄糖代谢水平是否相关。方法 42只雄性Wistar大鼠随机（随机数字法）分为假手术组（n=6）及实验组（n=36），通过静脉注射维库溴铵建立窒息型CA模型，实验组根据CA时间不同分为CA4、CA6、CA8组（每组n=12），分别于CA4、6、8 min后开始心肺复苏。记录复苏相关数据，自主循环恢复（restoration of spontaneous circulation, ROSC）24 h、72 h行正电子发射型计算机断层显像（positron emission tomography, PET）检测脑葡萄糖代谢最大标准化摄取值（the maximum standardized uptake value, SUVmax）, 并进行神经功能缺损评分（neurological deficit score, NDS）；ROSC 72 h检测脑组织病理损伤、细胞凋亡和己糖激酶（hexokinase, HXK） I蛋白的表达。结果 ROSC后各实验组大鼠脑SUVmax、NDS、HXK I蛋白表达下降，CA时间愈长，上述指标下降愈明显；ROSC后各实验组大鼠损伤的神经元及凋亡指数增加，CA8组多于CA6组及CA4组（P〈0.05），CA6组多于CA4（P〈0.05）; SUVmax与NDS呈显著正相关（P〈0.05）、与损伤的神经元数及凋亡指数均呈显著负相关（P〈0.05）。结论 CA后脑损伤程度与脑葡萄糖代谢水平密切相关， PET可能成为评估CA后脑损伤的一种手段。

Objective To determine the relationship between brain injury and cerebral glucose metabolism in rat model of cardiac arrest. Methods Asphyxia-induced cardiac arrest model was established. Forty-two male Wistar rats were randomly assigned to sham or experimental groups. Rats in the CA4,CA6 and CA8 group were treated with cardiopulmonary resuscitation（CPR） 4 min, 6 min and 8 min after cardiac arrest, respectively. The maximum standardized uptake value （SUVmax） of glucose was detected by PET, and neural deficit score （NDS） were evaluated at 24 h and 72 h after ROSC. The numbers of injured neurons and apoptotic cells and the protein level of hexokinase I （HXK I） were measured at 72 h after ROSC. Results SUVm^x, NDS and the level of HXK I were all decreased after ROSC, and interestingly, this declination of these markers was correlated with the prolongation of the duration of CA, the longer duration of CA the more declination of these biomarkers. Accordingly, the number of injured neurons and apoptotic cells increased were correlated with duration of CA, and thus CA8 group had greater numbers of those cells than CA6 group and CA4 group （P〈0.05）,and CA6 group had greater numbers of those cells than CA4 group（P〈0.05）. In addition, the SUVmax was positively correlated with NDS （P〈0.05）, and negatively correlated with the numbers of injured neurons and apoptotic index（P〈0.05）. Conclusions The degree of brain injury is associated with cerebral glucose metabolism, and PET may become a novel method to assess the severity of brain damage after CA.