脊髓冲击伤后应用低剂量FK506抑制iNOS表达及神经细胞凋亡

目的观察大鼠脊髓冲击伤后应用低剂量FK506对诱导型一氧化氮合酶（iNOS）表达及神经细胞凋亡的抑制作用。方法45只成年雄性wIstar大鼠，根据改良Allen法制备大鼠脊髓冲击伤模型。暴露脊髓T10节段，以重量为10g的铁锤从4cm高处自由落下，造成T10段脊髓冲击伤。假手术组5只、对照组和实验组各20只。实验组在脊髓损伤后5min一次性经尾静脉注射FK506（0．3mg／kg），其余两组以相同方法给予0．9％的生理盐水。于伤后不同时间点取材，行苏木精一伊红染色观察损伤脊髓组织病理变化，原位末端脱氧核糖核苷酸转移酶介导dUTP标记技术检测神经细胞凋亡，逆转录聚合酶链反应（RT-PCR）和免疫组织化学染色检测iNOSmRNA和蛋白的表达，同时采用BBB评分法进行后肢运动功能评价。结果实验组病理学观察和行为学评分明显优于对照组（P〈0．05，P〈0．01）；神经细胞凋亡在实验组较对照组明显减少（P〈0．05）；i—NOSmRNA和蛋白的表达均于伤后7d迭高峰，两者表达实验组明显低于对照组（P〈0．05，P〈0．01）。结论FK506能抑制大鼠脊髓损伤后iNOS表达及神经细胞凋亡，减轻继发性损害从而改善脊髓损伤后的功能恢复。

Inhibitive effect of low-dose Tacrolimus on expression of inducible nitric oxide synthase and neuronal apoptosis in rats following contusion spinal cord injury

Objective] To examine the inhibitive effect of low-dose Tacrolimus on expression of inducible nitric oxide synthase (iNOS) and neuronal apoptosis in rats following contusion spinal cord injury (SCI). Methods] Forty-five male Wistar rats were divided randomly into sham-operation group, control group and experiment group. The rat contusion SCI model was prepared according to the modified Allen method. After exposure of T10 spinal cord, the T10 segment was injured by a 10 g weight falling down from 4 cm high...