选择性COX-2抑制剂对大鼠脊髓损伤后细胞凋亡的影响相关性实验研究

目的:在建立大鼠脊髓损伤模型基础上,不同时间点观察选择性COX-2抑制剂对脊髓胶质细胞,神经元凋亡的影响,以期为临床急性脊髓损伤的治疗提供理论依据。方法:健康成年大鼠72只,随机分为两组,其中单纯损伤组(单纯打击损伤)36只,COX-2组(手术加COX-2)36只。脊髓损伤动物模型的制备:用自制A1len打击器2 5gcm致伤力撞击脊髓,制成脊髓损伤动物模型。COX-2组每天肌注帕瑞昔布(5 mg/Kg)直至处死,单纯损伤组仍每天肌注生理盐水0.5 ml直至处死。常规制成脊髓切片,给于Bcl-2检测,TUNEL原位末端标记,检测大鼠脊髓损伤后细胞凋亡的情况。结果:Bcl-2蛋白检测:在脊髓损伤后的第1天,脊髓组织即开始较高表达Bcl-2蛋白。单纯损伤组Bcl-2高峰发生在损伤后3天,而COX-2组伤后l天达到高峰,此时Bcl-2蛋白不仅表达在神经细胞中,更多的在胶质细胞中大量表达,且此状态一直维持到伤后14天才开始下降,伤后2l天仅少量表达;(P<0.05)。TUNEL原位标记检测:单纯损伤组24小时已山现不少阳性细胞,以胶质细胞为主,3～8天达到高峰,此后逐渐回落,但2l天时仍有阳性细胞,应用帕瑞昔布治疗后,凋亡细胞明显减少(P<0.05)。结论:本研究证明,选择性COX-2抑制剂在脊髓损伤中通过改善微循环,促进Bcl-2蛋白的表达,清除氧自由基,抗氧化作用能够抑制脊髓损伤早期神经细胞和胶质细胞的凋亡,从而减轻脊髓继发性损伤,促进脊髓神经功能的恢复。所以SCI后早期应用选择性COX-2抑制剂配合其它药物阻止神经细胞和胶质细胞的凋亡可能有助于减轻SCI的损害程度,促进脊髓神经功能的恢复,为SCI的治疗提供一个新的途径。

Effect of Pareeoxcb on Apoptosis Following Acute Spinal Cord Injury in Rats

Objective:To explore the Parecoxib on apoptosisfollowingspinal cord injury in different time in rats model of spinal cord injury.Methods:72 healthyratswerechosen andtheirbody weight varied from 250 gram to 310 gram.The rats were divided into two groups randomly:controlled group(36)and cox-2 group(36).All of rats spinal cord injury model were established with ALLEN bump,equipment(25g cm).The model of COX-2 group injected parecoxib(5mg/Kg) every day until they were sacrificed.The model of controlled group injected NS(0.5ml/d)every day until they were sacrificed.Fabrication of tissue section:after spinal cord injury 1d,3d,5d,8d,14d,21d,we sacrificed rats inbatch.4% formaldehydum polymerisatum were pured into the cardiac muscle and fixed for 24h.Then obtain the specimen of spinal cord from T5 to T13.Establishing slices,HE dyeing,bcl-2 dectation,terminal doxynucleotidyl transferase-mediated dUTP nick end labeling(TUNEL).Results:Bcl-2 dectation:Duringthefirst day after spinal cord injury,we found many bcl-2 protein in the spinal cord tissue.In control group,they reached the peak on the third day after spinal cord injury.In COX-2group,they reached the peak on the eight hday after spinal cord injury,Bcl-2protein were moreinglial cells than those innervecells.They begn to decrease after the for teenthday of spinalcordinjury(P<0.05).Tunel dectation:In control group,after 24 hours,there many positive ceils,most of them are gliao cells,it reached the peak after 3-8 day,and then,they were decreased gradually,in cox-2 group,positivecells obviouslylessthanthoseOfcontrolgroup(P<0.05).Conclusion:Fromthe lnvestigate,we proved that parecoxib could improve the microcirculation,get rid of oxygen free radieal,resist oxygenation,so as to restrainthe apoptosis of nerve cell and glial cell,lesson spinal cordinJury,improveTOTecoverspinalnerve.Therefore,duringearly time of spnalcord injury,we made use of parecoxib with other medicine,it should lesson spinal cord injury and provide a new methodfortreatment of spinal cord injury.