大剂量甲基强的松龙对大鼠损伤脊髓中碱性成纤维细胞生长因子变化的影响

Effect of Large Dose Methylprednisolone on the Change of Endogenous Basic Fibroblast Growth Factor in Rats After Spinal Cord Injury

〖目的〗应用大剂量甲基强的松龙(MP)对脊髓损伤进行干预治疗,探讨其对脊髓神经细胞中内源性碱性成纤维细胞生长因子(bFGF)变化的影响.〖方法〗40只wister大鼠分为三组:未损伤未给药组(A),损伤后注射生理盐水组(B),损伤后注射MP组(C).利用Allen氏重物坠击法(weight drop,WD)技术,以2.5g×10cm致伤力造成T8脊髓损伤模型,C组分别于术后即刻经尾静脉按首次剂量30 mg/kg注射MP,以后按5.4 mg/(kg@h),共23 h,分4次静推;B组在同时间点注入等量生理盐水.术后于2 d、5 d、12 d、28 d取A、B、C各组损伤部位脊髓组织作bFGF的免疫组化检测.〖结果〗在各个时间点上,大剂量MP可以显著地提高bFGF的表达.〖结论〗大剂量MP可能通过提高损伤脊髓组织中bFGF的表达,来发挥受损脊髓神经细胞的营养作用.

Objectives To explore the effect of large dose methylprednisolone(MP) on the change of endogenous basic fibroblast growth factor (bFGF) in nerve cells of rats after interfering treatment of spinal cord injury(SCI). Methods) Forty Wister rats were randomly divided into normal (n=8), control (n=16) and experiment group (n=16). In the normal group, all rats were not operated upon before sacrifice, but in both control and experiment groups, all rats were subjected to a 25gx 10 cm weight-drop SCI (Allen's method) at the T8 level respectively. For the experiment group, the rats were treated by intravenous injection of MP 30 mg/kg through the caudal vein in the first hour and 5.4 mg/(kg-h) infusion for 23 hours. The equal volume of normal saline solution was given to the rats of control group for the same duration.. Three groups rats were sacrificed at 2 d, 5d, 12d. 28d after injury ,and spinal cord tissue in the injured area was separated and made into sections. The bFGF protein levels were estimated by immunohistochemical method. Results In normal group, bFGF located within nuclei of astrocytes in grey matter and in cytoplasm of some neurons, its expression was much increased after SCI in rats. Intravenous injection of large dose methylprednisolone could prominently promote bFGF expression at all intervals. Conclusion Our findings suggest that bFGF may play an important role in selfrepairing and regeneration after SCI, and large dose methylprednisolone can improve greatly neurotrophic restoration of injured spinal nerve cells by enhancing the expression of endogenous bFGF .