大剂量甲基强的松龙对大鼠脊髓急性损伤细胞凋亡和bFGF变化的影响

Preventive Effects of Large Dose Methylpednisolone on Neural Cell Apoptosis and Change of Basic Fibroblast Growth Factor in Rats After Acute Spinal Cord Injury

目的应用大剂量甲基强的松龙 (MP)干预急性大鼠脊髓损伤 ,以探讨其对神经细胞凋亡和碱性成纤维细胞生长因子 (bFGF)的影响。方法采用改良Allen氏WD法制造急性脊髓损伤 (ASCI)模型 ,对 1 0 4只雌性wister大白鼠随机分为A、B、C三个组 ,其中A为细胞凋亡组 ,B为bcl 2组 ,C为bFGF组。每组又分为两个亚组 :大剂量MP治疗组和生理盐水组。术后d2 、d5、d2 8取损伤部位脊髓组织做以下检测 :①HE染色进行形态学观察 ;②TUNEL法检测凋亡细胞比例 ;③免疫组化检测bcl 2基因蛋白和bFGF。结果所有动物HE染色组织形态学观察和TUNEL法均证实有凋亡现象的存在 ,d2 开始出现 ,d5达高峰 ,d2 8开始下降 ;应用大剂量MP可以减少脊髓组织神经细胞发生凋亡的比例 ;在各个时间点上 ,大剂量MP可以显著地提高bcl 2和bFGF蛋白的表达。结论大剂量MP可以通过提高bcl 2和bFGF的表达 ,来发挥抑制ASCI神经细胞凋亡和营养神经细胞的作用 ,从而减轻了ASCI后的继发性损害程度。

ObjectivesTo explore the preventive effects of large dose methylprednisolone(MP) on neural cell apoptosis and change of basic fibroblast growth facto (bFGF) in rats after acute spinal cord injury (SCI).MethodsAnimal SCI model was established by modified Allen's WD method. One hundred and four Wister rats were divided into three groups: Group A, apoptosis; Group B, B cell lymphoma/leukemia 2 gene (bcl 2); and Group C, bFGF, respectively. Each group was redivided into two subgroups , including MP treated subgroup and normal saline treated subgroup. The rats were sacrificed at d 2, d 5, d 28 after injury , spinal cord tissue was collected and sections were made to do following examinations: ① Morphological observation on hematoxylin and eosin (HE) stain ; ② Detection of apoptotic cell proportion by TUNEL techniques ; ③ Detection of bcl 2 protein and bFGF with immunohistochemical method.ResultsThe existence of apoptosis in neurocytes after SCI was confirmed by HE staining and TUNEL techniques . Most of apoptotic cells were oliogodendrocytes. The apoptosis began to appear at d 2 after injury, reached its peak at d 5 and declined at d 28 . Administration of large dose MP reduced the proportion of apoptotic neurocytes in spinal cord, and elevated very significantly the expression levels of bcl 2 and bFGF proteins at all time points as compared with those in control subgroup.ConclusionLarge dose MP can inhibit the apoptosis of neurocytes during SCI and provide neurotrophic function by enhancing the expression of bcl 2 and bFGF gene , thereby it would ameliorate the degree of secondary injury after SCI.