低血压对颈动脉狭窄兔脑损伤的作用

The effect of hypotension on rabbit brain injury induced by carotid stenosis

目的观察不同干预所致低血压时双侧颈动脉中度狭窄家兔模型血浆神经元特异性烯醇化酶（neuron-specificenolase，NSE）及S100β浓度的变化，探讨围术期低血压对颈动脉狭窄兔脑组织的损伤作用。方法选择成年家兔建立双侧颈动脉中度狭窄家兔模型，采用完全随机法分为4组，除对照组外，其他3组分别采用放血，硝酸甘油，丙泊酚使血压降低20％～30％并维持20min后恢复血压，分别于恢复血压后7．5、24h取血液标本，测定血清中NSE及S100β蛋白，将脑损伤的指标做比较。结果与对照组比较3个降压组的血液标本中NSE及S100β 在各个观测时间点的值均升高，差异有统计学意义（P〈0．05）。丙泊酚组在降压7．5h的NSE及S100β 的表达值分别为（1487±19）μg/L和（592±10）μg/L，与放血组、硝酸甘油组比较，各时间点NSE蛋白表达指标的升高值较小，差异有统计学意义（P〈0．05）；S100β蛋白的表达较其余两个实验组低，差异有统计学意义（P〈0．05）。结论对于双侧颈动脉中度狭窄兔模型，放血、硝酸甘油及麻醉药物引起的血压降低20％～30％均引起NSE及S100β蛋白的表达升高，其中丙泊酚组的升高程度相对较低，可能与丙泊酚的脑保护作用有关。

Objective To observe the changes of neuron-specific enolase （NSE）and S100β concentration in plasma of the bilateral carotid moderate stenosis rabbits following hypotension induced by different interventions, and to explore the injury effect of perioperative hypotension on carotid stenosis rabbit brain. Methods Choose the adult rabbit to establish bilateral carotid moderate stenosis rabbit model. The rabbits were randomly divided into four groups, in addition to the control group, the other three groups rabbits all decreased blood pressure by 20%-30% induced by bloodletting, nitroglycerin and propofol, and maintain for 20 min, than restore blood pressure, Took blood samples, after blood pressure restoration 7.5, 24 h respectively and measured NSE and S100β protein in serum, then compared with the extent of brain damage. Results Compared with the blood samples of the control group, NSE and S100β values in each observation time point all increased in three hypotension groups, and there wree significant difference （P〈0.05）. NSE and S100β values were （1 486.51±19.22） μg/L and （592.13±10.09） μg/L respectively in propofol group after decreasing blood pressure 7.5 h, NSE protein expression index increased a little than the bloodletting group, nitroglycerin group at each time point, There were significant difference among these groups （P〈0.05）. S100β protein expression was decreased when compared with the other two experimental groups at 7.5 h, and there was, significant difference （P〈0.05）. Conclusions For the moderate bilateral carotid stenosis rabbit model, the expressions of NSE and S100β protein are both increased when blood pressure is reduced by 20%-30% induced by bloodletting, nitroglycerin and narcotic drugs. The increase degree in propofol group is relatively light, which may be related to the cerebral protective effects of propofol.