异氟醚预处理对大鼠脊髓损伤时炎性反应的影响

Effect of isoflurane preconditioning on inflammatory responses during spinal cord injury in rats

目的：评价异氟醚预处理对大鼠脊髓损伤时炎性反应的影响。方法雄性成年SD大鼠60只，体重250～300 g ，采用随机数字表法分为3组（ n＝20）：假手术组（S组）、脊髓损伤组（SCI组）和异氟醚预处理组（I组）。采用重物坠落法制备外伤性脊髓损伤模型。I组吸入2％异氟醚2 h ，结束后24 h时制备脊髓损伤模型。造模后第7天进行神经功能评分；评分结束后，各组随机取5只大鼠，采集脊髓标本，HE染色后行存活神经元计数；余15只大鼠采用Western blot法测定脊髓NF-κB和IL-1β的表达水平。结果与S组比较，SCI组神经功能评分降低，脊髓存活神经元计数减少，脊髓NF-κB和IL-1β表达上调（ P＜0.05）；与SCI组比较，I组神经功能评分升高，脊髓存活神经元计数增多，脊髓NF-κB和IL-1β表达下调（ P＜0.05）。结论异氟醚预处理对大鼠脊髓保护作用的机制与抑制炎性反应有关。

Objective To evaluate the effect of isoflurane preconditioning on inflammatory responses during spinal cord injury （SCI ） in rats .Methods Sixty adult male Sprague-Dawley rats ,weighing 250-300 g , were randomly divided into 3 groups （ n= 20 each ） using a random number table ：sham operation group （S group） , SCI group , and isoflurane preconditioning group （I group ） . The animals were anesthetized with intraperitoneal pentobarbital sodium 40 mg/kg .SCI was produced by a weight-drop contusion at the T10 level .The rats inhaled 2% isoflurane for 2 h ,and the model was established at 24 h after the end of isoflurane inhalation in I group . Neurological function was assessed and scored by using the the Basso , Beattie , Bresnahan （BBB ） Locomotor Rating Scale on 7 days after SCI .Five rats in each group were then chosen and spinal cord specimens were obtained and cut into sections which were stained with haematoxylin and eosin for determination of the viable neuron count .Fifteen rats in each group were sacrificed and the spinal cord was removed for detection of nuclear factor kappaB （NF-κB ） and interleukin-1β （IL-1β） expression （by Western blot ） .Results Compared with S group ,BBB score and the number of viable neurons were significantly decreased ,and the expression of NF-κB and IL-1βprotein was up-regulated in SCI group （ P〈0.05） .Compared with SCI group ,BBB score and the number of viable neurons were significantly increased ,and the expression of NF-κB and IL-1βprotein was down-regulated in group I （ P〈0.05 ） .Conclusion The mechanism by which isoflurane preconditioning protects the spinal cord is related to inhibition of inflammatory responses in rats .