常温缺血后选择性超深低温对猴脑Bc1-2和Bax表达的影响

The Effects of Selective Cerebral Ultra-Profound Hypothermia on Bc1-2 and Bax Expression in Brain Tissues of Monkeys after Occlusion of Cerebral Blood Flow under Different Time Limits

目的观察猴脑常温缺血0 min、10 min、15 min、20 min后选择性脑超深低温断血流复苏对Bc1-2和Bax蛋白表达的影响.方法健康成年恒河猴15只,雄性,随机分为4组,0 min组(双侧颈动脉常温下阻断0 min后行脑选择性超深低温灌注,即热缺血0 min,简称0 min组,n=4),10 min组(方法同上,n=4),15min组(n=4),20 min组(n=3).依照昆明医学院第二附属医院神经外科前期方法建立模型,术后行神经功能缺失评分.实验猴灌注或复苏死亡后立即开颅取脑,长期存活猴饲养到术后4周处死开颅取脑.免疫组织化学法检测猴额叶神经细胞Bc1-2和Bax的表达水平.结果 0 min组、10 min组安全复苏并长期存活,术中、术后血流动力学稳定,术后神经功能评分无异常;15 min组长期存活2只,重残1只,死亡1只;20 min组则全部死亡.免疫组化结果表明:4组间相互比较,Bax的表达逐渐增高(P<0.05).10 min组、15 min组、20 min组3组间猴脑额叶Bc1-2表达明显逐渐降低,3组间差异有统计学意义(P<0.05);0 min组与20 min组比较差异有统计学意义(P<0.05);0 min组较10 min组、15 min组猴额叶Bc1-2的表达无明显差异,无统计学意义(P>0.05).结论超深低温能显著降低Bax的表达,促进Bc1-2的表达,从而起到脑保护的作用.

Objective To investigate the influence of selective cerebral ultra-profound hypothermia reperfusion on the expression of Bc 1-2 and Bax in nerve cells in experimental monkeys after occlusion of cerebral blood flow for different time （0, 10, 15 and 20 rain）. Methods 15 healthy adult male rhesus monkeys were randomly divided into 4 groups： 0 rain group （repeffusion 0min after bilateral internal carotid arteries blockage, n=4）, 10mingroup （the same as way, n=4）, 15mingroup （n=4）, 20mingroup （n=3）. The model was established by right internal carotid artery （ICA） infusing and internal jugular vein （ IJV ） extracting （referring to the last way）. We executed the monkeys 4 weeks after operation for long-term survival monkeys. lmmunohistoehemical technique was used to detect the level of Bcl-2 and Bax protein expression in the four groups respectively. Results All monkeys in 0rain and 10rain groups （n = 8） survived till they were executed, andtheir preoperative and postoperative hemodynamical parameters were steady and nerve function scores were normal. 2 monkeys survived for long-term, 1 monkey was disabled and 1 died in 15min group （n =4）. All monkeys died in 20 min group, lmmunohistochemical test showed that Bax protein expression was gradually elevated from 0min group to 20min group, and there was a significant difference among four groups （P 〈 0.05）. There was no significant difference among 0 min group, 10 min group and 15 min group （P 〉 0.05） , but Bcl-2 protein expression was lower in 20 min group, ompared with the former three groups （P 〈 0.05）. Conclusion Selective ultra-profound hypothermia has significant brain protective effects in monkey after brain ischemia through upregulating the Bcl-2 protein expression and downregulating the bax protein expression.