不同年龄大鼠坐骨神经损伤后睫状神经营养因子对脊髓组织中Caspase3表达的影响

目的　观察睫状神经营养因子 (CNTF)对天冬氨酸特异酶切的半胱氨酸蛋白酶 (Caspase3)在坐骨神经损伤后不同年龄大鼠脊髓组织中表达的影响。方法　幼年、成年、老年Wistar大鼠各 2 70只 ,随机分为正常组 (1 8只 )、CNTF组 (1 2 6只 )和生理盐水组 (1 2 6只 )。CNTF组和生理盐水组切出长 2mm右侧坐骨神经 ,用硅胶管连接近、远侧神经残端制作神经再生小室 ,CNTF组再生小室内注入 2 5 μg/ml重组CNTF1 5 μl,生理盐水组再生小室内注入生理盐水 1 5 μl,CNTF组和生理盐水组分为术后 1、3天和 1、2、4、8、1 2周组。利用免疫组织化学、Westernblotting检测脊髓Caspase3的分布与表达强度变化 ,进行Caspase3活性测定。结果　损伤后各年龄组伤侧脊髓Caspase3蛋白表达增强 (P <0 .0 5或 0 .0 1 ) ,以前角运动神经元变化最为明显 ,幼年、成年、老年CNTF组Caspase3表达较生理盐水组减弱 (P <0 .0 5或 0 .0 1 ) ;各组对侧未伤侧与正常组比较 ,差异无显著性意义 (P >0 .0 5 )。幼年、老年及成年生理盐水组于损伤侧脊髓Caspase3活性升高 ,各时相点幼年大鼠Caspase3活性高于老年及成年 (P <0 .0 5或 0 .0 1 ) ,幼年、成年、老年CNTF组Caspase3活性低于生理盐水组 (P <0 .0 5或 0 .0 1 )。生理盐水组及CNTF组对侧未伤侧Ca

Effects of ciliary neurotrophic factor on caspase3 in spinal cord in rats of different ages after sciatic nerve injury

Objective To investigate effects of ciliary neurotrophic factor (CNTF)on Caspase3 in spinal cord in rats of different ages after sciatic nerve injury.?Methods Two hundred seventy young,adult or old Wistar rats were studied at 1,3 days and 1,2,4,8,12 weeks following transection of sciatic nerve.?Their sciatic nerves were transected and repaired with collagen tubules.?Recombined CNTF or saline solution were injected in collagen tubules.?The expression of caspase3 were detected by immunohistochemistry and western blotting.?Caspase3 activity was detected by Caspase3 activity assay.?Results The expression of caspase3 in the injured spinal cord increased after injury (P<0.05 or 0.01).?The expression of caspase3 was mainly localized to neuronal cells in the spinal ventral horn.?The caspase3 protein in CNTF group after injury was less than that found in saline group.?There were no difference in the contralateral side between saline,CNTF and normal groups after injury in rats of different ages(P>0.05).?The activity of caspase3 increased in young group,adult and old group(P<0.05 or 0.01).?The caspase3 activity in young group was higher than that in adult or old group(P<0.05 or 0.01).?The activity of caspase3 in CNTF group after injury was less than that found in saline group.?There was no difference in the contralateral side between saline, CNTF and normal groups after injury in rats of different ages(P>0.05),except young group at 12w after injury.?Conclusion The expression and activity of Caspase3 increased in rats of different ages after sciatic nerve injury.?CNTF can decrease the expression and activity of Caspase3 after sciatic nerve injury,and effects of CNTF were gradually decreased as the animal aged.