辛伐他汀预处理对大鼠脊髓缺血再灌注损伤后炎症介质及NOS的影响

Effects of Simvastatin pretreatment on expression of inflammatory mediators and NOS in rats subjected to spinal cord ischemia-reperfusion injury

目的:探讨辛伐他汀预处理对大鼠脊髓缺血再灌注损伤后肿瘤坏死因子(Tumer nectosis factor-α,TNF-α)、白介素-10(Interleukim-10I,L-10)、S-100蛋白以及一氧化氨合酶(Nitric oxide synthase,NOS)亚型的影响。方法:雄性SD大鼠72只,随机分为假手术组(C组),缺血再灌注损伤组(I/R组)和辛伐他汀预处理组(Si组)(20 mg/kg灌胃,术前连续3 d),采用Zivin改进法建立模型,造模成功后,分别在再灌注6、12、24 h,取脊髓组织作HE形态学染色;ELISA法测定组织TNF-αI,L-10;应用免疫组化法检测脊髓S-100蛋白;比色法检测组织NOS各亚型以及测定24 h内神经功能评分。结果I:/R组各时间点TNF-α与S-100蛋白表达量呈显著正相关;与I/R组相比,Si组形态学的损伤改变较轻;Si组能提高再灌注后12、24 h神经功能评分,降低各时间点TNF-α含量及再灌注后12、24 h S-100蛋白的表达,提高再灌注6、12 h结构型NOS(Constitutcive NOS,cNOS)活性,降低再灌注12、24 h诱导型NOS(Inducible NOSi,NOS)活性,但IL-10含量在再灌注24 h上升不如I/R组明显。结论:脊髓缺血再灌注损伤后,组织S-100蛋白的表达与炎症反应具有一定相关性。辛伐他汀预先给药后,S-100蛋白的表达减少,脊髓缺血再灌注损伤减轻,神经功能得到改善,其机制可能与减少TNF-α的释放,上调cNOS表达,降低iNOS活性有关,但辛伐他汀不能通过增加IL-10的释放而发挥保护作用。

Objective：To investigate the effects of simvastatin pretreatment on expression of TNF-α,S-100 protein,IL-10 and the subtypes of NOS in rats subjected to spinal cord ischemia-reperfusion injury.Methods：72 healthy male SD rats were randomly divided into three groups：sham operation（group C）,ischemia-reperfusion injury（group I/R） and simvastatin pretreatment（group Si）（20 mg/kg for 3 days via an orogastric tube before the operation）.Using Zivin improvements methods under the renal aortic cross-clamping to establish model,then all treated rats were randomly divided into three subgroups at reperfused 6,12,24 h for HE staining,ELISA method of the determination of tumor necrosis factor-α（TNF-α） and interleukin-10（IL-10）,immunohistochemical staining of S-100 protein,colorimetric detection of the subtypes of NOS（nitric oxide synthase） in spinal cord and neurological function scores within 24 h.Results：The expression of TNF-α and S-100 protein in group I/R was significantly correlated at different time points.Simvastatin pretreatment can reduce spinal cord ischemia-reperfusion injury,inhibiting the excessive secretion of S-100 proteins,reducing TNF-α content and iNOS（Inducible NOS） activity,increases cNOS（Constitutcive NOS）,improving neurological function score at 12,24 h after I/R.Conclusion：The expression of tissue S-100 protein is related with the inflammatory response subjected to spinal cord ischemia-reperfusion.Simvastatin can inhibit S-100 protein,reducing spinal cord ischemia-reperfusion injury and improving neurological function,which may be related to the reduction of TNF-α and iNOS activity,increasing cNOS,However,simvastatin can＇t raise IL-10 to produce the protective effect.