局部亚低温对大鼠全脑缺血再灌注后血清S100B蛋白的影响

目的探讨局部亚低温对大鼠全脑缺血再灌注后血清S100B蛋白的影响。方法 24只SD雄性大鼠随机分为3组：假手术组（S组）、缺血再灌注组（IR组）、亚低温组（H组）,每组8只。采用双侧颈总动脉夹闭＋基底动脉丝线提拉法制备全脑缺血再灌注损伤模型,全脑缺血10min再灌注6h。实验过程中监测大鼠脑血流图并测定动脉血气。H组再灌注前即刻经股静脉缓慢注射10℃0.9%氯化钠溶液3.5ml,冰块包绕头部,60W白炽灯照射身体。控制鼓膜温度在32～34℃,直肠温度同时降低,20min左右升至并维持在37.5～38.3℃。低温维持3h,3h后60W白炽灯照射身体缓慢复温。实验结束后测定大鼠血清S100B蛋白浓度;用干（110℃24h烘干）、湿重法计算左侧大脑半球脑水含量。结果与S组比较,IR组S100B蛋白浓度、脑含水量升高（P〈0.05）;与IR组比较,H组S100B蛋白浓度、脑含水量降低（P〈0.05）。结论局部亚低温降低大鼠全脑缺血再灌注后血清S100B蛋白的表达量,对全脑缺血再灌注损伤大鼠有保护作用。

Effect of local mild hypothermia on serum S100B against ischemia-reperfusion injury in rats

Objective To investigate the effect of local mild hypothermia on serum S100B against ischemia-reperfusion injury in rats.Methods Twenty-four male Sprague-Dawley rats weighted 200～250 g were randomly divided into 3 groups （n=8 each）：sham operating group（S）;ischemia-reperfusion group （I/R）;mild hypothermia＋ I/R group（H）.The model of cerebral ischemia-reperfusion injury in rats was induced by occlusion of bilateral common carotid arteries and basilar artery for 10min,then reopening them for 6h.The rats in group H were provided 3h local mild hypothermia after the injection of 10℃ normal saline 3.5ml via femoral vein at the time of reperfusion,combing with 60W incandescent lamp shotting body,with pieces of ice surrounding head.1min after reperfusion periost temperature began to drop in,then maintained at 32～34℃ during the hypothermia.The rectum temperature dropped in too,after 20min went up to normothermia under shotting of incandescent lamp.The hypothermia maintained for 3h,then rewarming slowly.When the experiment was completed,the vein blood samples were taken from internal jugular vein of rats,and serum levels of S100B protein were detected by ELISA.Then the animals were decapitated and brain water content was determined by dry wet weight method on the left.Results As compared with group S,the serum S100B protein levels and brain water content in I/R group were significantly increased （P0.05）.As compared with I/R group,the serum S100B protein levels and brain water content content in group H were significantly decreased （P0.05 ）.Conclusion The local mild hypothermia can decrease concentration of serum S100B induced by ischemia-reperfusion injury in rats and has a protective effect on the brain against I/R injury.