大鼠坐骨神经慢性压迫损伤后脊髓感觉神经元发生非凋亡性细胞程序性死亡

PARAPTOSIS FORMS OF PROGRAMMED CELL DEATH PRESENT IN SENSORY NEURONS AT SPINAL CORD DORSAL HORN AFTER CHRONIC CONSTRICTION INJURY OF THE SCIATIC NERVE IN RATS

目的:观察大鼠坐骨神经慢性压迫损伤后脊髓背角感觉神经元是否发生非凋亡性细胞程序性死亡(paraptosis)。方法:成年雄性SD大鼠20只,随机分为正常组,手术组。手术组建立慢性压迫性损伤(CCI)模型,又分为术后3d、7d、14d组。实验动物以4%多聚甲醛PBS液灌注内固定,取与坐骨神经相应的腰4～腰6节段脊髓,于2.5%戊二醛中固定,透射电镜观察左侧脊髓背角浅层神经元超微结构并摄片。结果:电镜下,术后3d组腰4～腰6节段脊髓左侧背角浅层神经元形态学典型变化为:细胞肿胀,胞膜完整,胞浆内大量空泡,核结构基本正常,符合paraptosis形式程序性细胞死亡表现;7d和14d组神经元形态变化:细胞皱缩、密度增大,核带增多及染色质浓聚贴附于核膜,符合凋亡表现。结论:坐骨神经损伤3d腰4～腰6节段脊髓背角浅层神经元发生了parapto-sis形式程序性细胞死亡。

Objective：To observe paraptosis forms of programmed cell death present in sensory neurons of spinal cord dorsal horn after chronic constriction injury of the sciatic nerve in rats. Methods：20 adult male SD rats were randomly divided into normal group and operated group. Chronic constriction injury （CCI） model was established in rats of operated groups. Rats in operated groups were divided into 3,7 and 14 days groups following surgery. All rats were perfused and fixed with 4% paraformaldehyde. L4-L6 dorsal horn were observed and taken photographs. Results： At 3 days following surgery, neuronal typical morphology changes： cell swelling, membrane integral, cytoplasmic vacuolizing and nuclear structure basically normal, which were in line with paraptosis forms of programmed cell death;At 7 and 14 days following surgery, neurons state changes： cell shrinkage, density increased, with increased nuclear and chromatin in the attached concentration of nuclear membrane, consistented with apoptosis. Conclusion： After sciatic nerve injury, paraptosis forms of programmed cell death present in the sensory neuron of superficial layer of the L4-L6 left spinal cord dorsal horn at 3 days following surgery.