胶质细胞源性神经营养因子对大鼠脊髓损伤后后肢运动功能及其运动诱发电位的影响

Effect of glial cell line drived neurotrophic factor on motor function of lower limbs and motor evoked potential after spinal cord injury in rats

目的 探讨胶质细胞源性神经营养因子 (GDNF)对大鼠脊髓损伤后后肢运动功能及其运动诱发电位 (MEP)的影响。 方法 将 30只SD雄性大鼠 (2 0 0～ 2 5 0g)随机分为对照组、等渗盐水 (NS)组和GDNF组 ,每组 10只。改良Allen方法致T13 段脊髓不完全损伤 ,蛛网膜下腔分别给予NS或GDNF 2 0 μl,伤后 1,5h和 1,3,5d评定后肢出现运动功能 (Salzman评分 )和检测MEP。 结果 脊髓损伤后后肢运动障碍 ,MEP波幅 (P1-N1峰峰值 )降低、潜伏期延长 ,对照组无变化。伤后1,5h和 1,3,5d ,NS组波幅分别恢复至伤前的 36 .7%、38.9%、47.1%、74.1%和 92 .3% ,潜伏期恢复至 112 .5 %、111.2 %、111.3%、10 5 .0 %及 10 3.5 % ;伤后 5h和 1,3dGDNF组波幅恢复明显优于NS组 ,伤后 1,3dGDNF组潜伏期恢复优于NS组 (P <0 .0 5 )。伤后 1,5h后肢运动功能无恢复 ,伤后1d开始恢复 ,伤后 3,5d明显恢复 ,其中GDNF组恢复显著优于NS组 (P <0 .0 1)。 结论 GDNF能够早期促进MEP波形的恢复 ,增强后肢运动功能的恢复 ;MEP恢复早于后肢运动功能恢复。

Objective To investigate the effect of glial cell line de rived neurotrophic factor (GDNF) on motor function of lower limbs and motor evo ked potential(MEP) after spinal cord injury (SCI) in rats. Methods Thirty healthy male SD rats weighing 200-250 g were divided into 3 groups, i.e., control group, Group NS and Group GDNF. NS or GDN F for 20 μl were respectively supplied through subarachnoid cavity after T 1 3 se gments of spinal cord were incompletely injured by modified Allen's crush method . Motor function of lower limbs was evaluated using Salzman's grading criteria. MEP was recorded 1, 5 hours and 1, 3, 5 days after SCI. R esults Distinct handicap of motor function in lower limbs presented, an d amplitude (peak-peak between P1 and N1) of MEP reduced, MEP prolonged both in Group NS and Group GDNF. Amplitudes of Group NS returned to 36.7%, 38.9%, 47.1%, 74.1% and 92.3% respectively. Delitescence returned to 112.5% , 111.2%, 111.3%, 105.0% and 103.5% respectively. Amplitudes in Group GDNF recovered better than that in Group NS 5 hours and 1, 3 days after SCI; and delitescence restored better in Group GDNF than that in Group NS 1, 3 days after SCI ( P <0.05). Th ere were no naked function recovery 1 hour and 5 hours after SCI. Function recov ered 24 hours postoperatively, and was obvious 3 and 5 days after SCI. The recov ery in Group GDNF preponderated over that in Group NS ( P <0.01). Con clusions GDNF can accelerate undee reversion of MEP and promote motor function recovery of spinal cord. Undee restoration of MEP begans earlier than t hat of motor function of lower limbs.