丙烯酰胺对小鼠坐骨神经捻挫损伤后有髓纤维变性和再生的影响

背景:Ola鼠是一种基因变异鼠,其周围神经轴突损伤后华勒氏变性速度比正常的6J鼠缓慢,增加损伤因素可能有助于了解Ola鼠的特性。目的:观察丙烯酰胺对捻挫损伤后C57BL/Ola(Ola)鼠和C57BL/6J(6J)鼠坐骨神经有髓纤维变性和再生的不同病理过程。设计:随机对照实验。单位:深圳市第二人民医院神经内科和吉林大学第一医院神经内科。材料:实验于1996-01/06在日本产业医科大学神经内科进行。选择成年Ola鼠和6J鼠各12只,Ola鼠和6J鼠各6只为实验组,其余各6只为对照组。方法:全部动物麻醉状态下暴露坐骨神经上段,用止血钳捻挫神经近端10s后缝合。实验组动物注射总剂量为350mg的丙烯酰胺,对照组动物同时腹腔注射等量生理盐水。坐骨神经捻挫损伤后14d,全部动物再次麻醉,取捻挫部位远端坐骨神经制备切片,测量并计算神经横截面积,有髓纤维密度和有髓纤维大小频率分布和每根神经的有髓纤维数目。主要观察指标:两组中01a鼠和6J鼠坐骨神经的有髓纤维密度、有髓纤维数目、有髓纤维最大直径、有髓纤维平均直径。结果:参加实验Ola鼠和6J鼠各12只全部进入结果分析。①Ola鼠没有发生华勒氏变性;而6J鼠可见有髓纤维变性和许多变性后新生小径有髓纤维。②实验组6J鼠坐骨神经总有髓纤维密度低于Ola鼠(P<0.05);总有髓纤维数目少于Ola鼠(P<0.01),以大径纤维数目减少明显(P<0.01);有髓纤维平均直径也明显小于01a鼠(P<0.01)。结论:Ola鼠捻挫伤后华勒氏变性速度极其缓慢,丙烯酰胺对这一特征没有影响;丙烯酰胺对6J鼠捻挫损伤后轴突的再生过程有抑制作用。

Effect of acrylamide on the degeneration and regeneration of rat myelinated fiber after sciatic nerve crush injury

BACKGROUND:Ola rats is a kind of rats with genovariation, who displays Wallerian degeneration after peripheral neuroaxonal damage that is slower than that normal 6J rats, thereby additional damage factor may help fully understand the property of Ola rats.OBJECTIVE: To observe the effect of acrylamide on the degeneration and regeneration of sciatic nerve medullated fibers following crush injury of C57BL/Ola (Ola) rat and C57BL/6J (6J) rat.DESIGN: Randomized controlled experiment.SETTING: Department of Neurology,Second People's hospital of Shenzhen; Department of Neurology of First hospital of Jilin University MATERIALS: This experiment was carried out in the neurological department in the University of Occupational and Environmental, Japan from January to June 1996. Twelve adult Ola rats and 6J rats were adopted and evenly randomly divided into experimental group and comparison group.METHODS: Rats were subjected to general anaesthesia, and then the proximal section of sciatic nerve was exposed and frustrated with hemostatic forceps for 10 s before suture. Rats in the experimental group were given intraperitoneal injection of acrylamide in a total dosage of 350 mg, which replaced by the same volume of physiological saline in comparison group.At 14 days after sciatic nerve torsion injury, all rats were anaesthetized again and the distal section of sciatic nerve was obtained and cut into slices, meanwhile the cross sectional area, the density and size frequency distribution of medullated fibers, as well as the number of medullated fibers in each nerve were determined.MAIN OUTCOME MEASURES: The density and size frequency distribution of sciatic nerve medullated fibers, as well as the number, the maximum diameter and the mean diameter of medullated fibers in two group of 0la rats and 6J rats.RESULTS: Totally 12 Ola rats and 6J rats entered the result analysis.① No Ola rat displayed Wallerian degeneration; But medullated fiber degeneration and following neonatal small diameter medullated fibers could be observed in 6J rats. ②In the experimental group, the total density of sciatic nerve medullated fibers in 6J rats was lower than that of Ola rat (P ＜ 0.05) ;with the total number of medullated fibers in 6J rats also less than that of Ola rat (P ＜ 0.01 ), which predominated by obviously reduced big diameter fibers (P ＜ 0.01); The mean diameter of medullated fiber in 6J rats was also obviously smaller than that of 0la rat (P ＜ 0.01 ).CONCLUSION: The Wallerian degeneration is extremely slow in Ola rat after torsion injury, which cannot be affected by acrylamide; while acrylamide has obvious inhibition on the axonal neogenesis in 6J rat after torsion injury.