鼠后肢周围神经缺血再灌注对脊髓腰膨大前角运动神经元超微结构的影响

The ultrastructure changes of motor neuron of anterior horn in lumbar enlargement of spinal cord after hindlimb ischemia and reperfusion in rats

目的 探讨大鼠后肢周围神经缺血再灌注对脊髓腰膨大前角运动神经元超微结构的影响及其内在关系。方法 采用无损伤动脉夹暂时阻断大鼠一侧髂总、髂内、髂外及股动脉的大鼠周围神经缺血的实验模型,透射电镜下观察不同缺血再灌注时间脊髓腰膨大灰质前角细胞的超微结构改变。结果 对照组神经元的超微结构形态正常,缺血6 h,8 h,12 h 3组均出现暗神经元改变。缺血 8 h组,除暗神经元改变外,还出现明确的细胞坏死。缺血12 h组,神经元暗细胞变与大片神经组织坏死并存,血脑屏障严重破坏。在缺血6 h,8 h,12 h各组内,随着再灌注时间的延长(60 h以内),神经元的损害明显逐渐加重。结论 大鼠后肢周围神经缺血再灌注可相应地引起脊髓腰膨大前角运动神经元超微结构的改变,可引起神经元的暗细胞变和坏死。在同一缺血组内,随着再灌注时间的延长,神经元的损害逐渐加重。

Objective To investigate the effect of ischemia and reperfusion of hindlimb in rats on ultrastructure changes of motor neuron of anterior horn in lumbar enlargement of spinal cord and their internal relation. Methods The model of temporary occlusion of the common iliac, internal iliac, external iliac and femoral artery was set up. The ultrastructure changes of motor neurons of anterior hom in lumber enlargement of spinal cord at various intervals was observed under transmission electron microscope. Results Normal neuron ultrastructure was found in the control group. Dark neurons were observed in all 3 groups (6, 8 and 12 hours intervals). The definitive neurons necrosis was found at 8 hours ischemia. Severe neurons necrosis and damage of blood-brain barrier were developed at 12 hours ischemia. In each group, the longer the reperfusion period (shorter than 60 hours), the more severe the damage of the neurons. Conclusion The ischemia and reperfusion injury to the peripheral nerve in hindlimb in rats can give rise to the ultrastructure changes of motor neuron of anterior horn in lumbar enlargement of spinal cord, resulting in dark neuron and neuron necrosis. As the duration of ischemia and reperfusion prolongs, the damage of neuron becomes more severe.