不同低温诱导方式对大鼠脑梗死急性期的治疗效果比较

Comparison of neuroprotective effects of hypothermia induced by different methods in rats with early cerebral ischemia

目的比较冰帽、全身低温及颈内动脉冷盐水灌注（ICSI）对于大鼠脑梗死急性期的治疗效果,为临床治疗急性脑梗死时不同低温方式的选择和ICSI的深入研究提供实验依据。方法 250~300 g SD大鼠随机分为模型组、冰帽组、全身低温组和ICSI组,用线栓法复制大脑中动脉栓塞2 h模型,各低温方式的目标温度为33~34℃维持20 min。再灌48 h后,进行神经行为学评分;取脑行2,3,5-氯化三苯四氮唑染色;干湿重法检测脑含水量;酶联免疫吸附法检测血清中神经元特异性烯醇化酶（NSE）、S100β和基质金属蛋白酶9（MMP9）的浓度。结果各低温方式均能降低大鼠梗死体积,其中冰帽能使梗死体积减小27.4%（P〈0.05）,而全身低温和ICSI能使梗死体积减小47.6%和61.6%（P〈0.01）。全身低温组和ICSI组的脑含水量低于模型组（P〈0.05）;冰帽组的含水量低于模型组,但并无统计学意义。各低温组中,仅有ICSI组的神经行为学评分与模型组有统计学差异（P〈0.05）。血清学方面,ICSI组的NSE和S100β的浓度显著低于模型组（P〈0.05）;全身低温组和冰帽组中各指标与模型组比较均无统计学意义。结论 ICSI对于脑梗死急性期的治疗效果要优于冰帽和全身低温,而全身低温比冰帽有更好的疗效。

Objective To compare the neuroprotective effects of intracarotid cold saline infusion（ICSI）,ice cap and systemic cooling in rats with early cerebral ischemia.Methods SD rats were randomly divided into model group,ice cap group,systemic cooling group and ICSI group（n=13）.Cerebral ischemia was induced by middle cerebral artery occlusion（MCAO） for 2 h.In the 3 hypothermic groups,the target temperature of 33-34 ℃ was achieved and maintained for 20 min.In each group,the neurological scores were recorded at 48 h after the reperfusion,and the brains were removed for measuring the infarct size using 2,3,5-triphenyltetrazolium chloride staining.The brain water contents and serum levels of neuron-specific enolase（NSE）,S100β and matrix metalloproteinase 9（MMP9） were also measured.Results Compared with the model group,the ice cap,systemic cooling and ICSI groups all showed significantly reduced infarct size by 27.4%（P0.05）,47.6%（P0.01） and 61.6%（P0.01）,respectively.The systemic cooling and ICSI groups,but not the ice cap group,had significantly lower brain water contents than the model group（P0.05）.Among the 3 hypothermic methods,only ICSI significantly improved the neurological scores（P0.05） and reduced serum NSE and S100β levels（P0.05）.Conclusion Of the 3 hypothermic groups,ICSI has the best neuroprotective effects,and systemic cooling produces better effect than ice cap in rats with ischemic stroke.