运动训练对大鼠损伤远端脊髓及骨骼肌血管内皮生长因子表达的影响

摘要

目的:明确运动训练对大鼠损伤远端脊髓及骨骼肌血管内皮生长因子(VEGF)表达的影响,探讨运动促脊髓损伤功能恢复的机制.方法:成年雌性SD大鼠24只,采用改良Allen撞击法制作T9不完全性脊髓损伤模型.术后随机分为损伤后1d组、1周组、训练组(术后1周开始训练,共4周)、对照组(未行训练).分别在损伤前、损伤后第1、2、3、4及5周时采用Basso-Beattie-Bresnahan(BBB)评分评定运动功能.取损伤后1d、1周,对照组及训练组大鼠L5-S1节段脊髓及腓肠肌新鲜组织,采用RT-PCR及Western blot法测定VEGF mRNA及蛋白表达.结果:①对照组与训练组BBB评分均较损伤后1周、2周明显提高,但训练组较对照组增加更为显著(P＜0.05)；②训练组脊髓及腓肠肌VEGF mRNA及蛋白表达较对照组、损伤后1d、1周组显著增加(P＜0.05)；对照组与损伤1周组、1d组比较脊髓及腓肠肌内VEGF表达差异无显著性(P＞0.05)；但1周组脊髓内VEGF较1d组表达增加(P＜0.05),而腓肠肌内VEGF表达较1d组降低(P＜0.05).结论:运动训练能有效诱导脊髓损伤大鼠远端脊髓及骨骼肌VEGF表达,促进运动功能恢复.%Objective:To determine the effects of exercise training on expressions of vascular endothelial growth factor(VEGF) in distal spinal cord and skeletal muscles of rats with spinal cord injury.rnMethod: Twenty-four female adult Sprague-Dawley rats were included. An animal model of incomplete spinal cord injury was established by using modified Allen's method at T9 level of spinal cord. Those rats were divided into 4 groups randomly as Id group, lweek post-injury group, control group(without training) and exercise group (trained by hody-weight-support-treadmill-training), Exercise training started at 1 week after injury lasted 10 min per time, twice a day, 5d per week, for 4 weeks. Locomotor function was evaluated using Basso-Beattic-Bresnahan (BBB) scale before injury and at the 1st d, 1st, 2nd, 3rd, 4th and 5th week post. Real time-PCR and Western blot were used to detect the expressions of VEGF mRNA and protein in spinal cord and gastrocnemius muscle. Result:① BBB scores in exercise group and control group were higher than that in lweek group and 2week post injury group. But BBB score in exercise group increased more significantly than that in control group (P<0.05). ② Expressions of VEGF mRNA and protein in distal spinal cord and gastrocnemius muscle in exercise group were higher than that in Id group, lweek post injury group and control groups,but there was no difference among control group, Id group and lweek post injury groups. Compared with Id group, in lweek group the expressions of VEGF mRNA and protein were higher in spinal cord, but lower in gastrocnemius muscles (P<0.05). Conclusion: Exercise training may promote the recovery of locomotor function and induce the expressions of VEGF mRNA and protein in distal spinal cord and skeletal muscle.