大鼠脊髓损伤后腓肠肌GDNF基因表达及意义

GDNF gene expression and its significance on gastrocnemius mucle of rats with injuried spinal cord

目的 探讨大鼠脊髓损伤后 ,后肢肌GDNFmRNA表达的变化及其意义。方法 选用SD雄性大鼠 30只 ,根据脊髓损伤时间随机分为 5组 ,即伤前、伤后 3、7、10及 2 1天组。采用Allen s方法致大鼠脊髓T13 段不完全性损伤 ,以 β Actin为内参照物 ,半定量RT—PCR方法 ,观察大鼠腓肠肌在脊髓损伤前、后不同时间GDNFmRNA表达。结果 脊髓损伤前GDNFmRNA在大鼠腓肠肌微量表达 ,脊髓损伤后 3天表达上调至 3倍 ,7天上调至 10倍 ,10天上调至 4倍 ,2 1天仍高于正常水平。结论 脊髓损伤后骨骼肌GDNFmRNA表达上调 ,可能是神经元通过“胞体—轴突—靶器官”途径的一种自我保护反应 ,用GDNF治疗脊髓损伤时应长期用药。

Objective To investigate the varieties and its significance of GDNF gene expression on hindlimbs of rats with crushed injury of the spinal cord (SCI) Methods 30 male SD rats were divided randomly into 5 groups(pro operation,3th,7th,10th and 21st after operation) based on the time of spinal cord injury produced with Allens method.GDNFmRNA expression on gastrocnemius mucle of the rats with spinal cord injury at different times after the injury were observed using semi quantitaive RT PCR method with β Actin as a inner consult.Results Minimal expression of GDNFmRNA was found in gastrocnemius mucle in the normal rats,and it up regulated 3 times 3 days after SCI,10 times 7 days,4 times 10 days and slight higher than normal level 21 days after SCI.Conclusion It may be one kind of self protective reaction of skeletal muscle to express high standard GDNFmRNA through 'motorneuron axon target' route in the early stage after SCI.GDNF should be supplied early and long term treatment of SCI.