右美托咪啶对脊髓损伤大鼠的神经保护作用

Neuroprotective effects of dexmedetomidine on spinal cord injury in rats

目的研究右美托咪啶对脊髓损伤(SCI)大鼠的神经保护作用及其机制。方法通过暴力撞击方式建立SCI大鼠模型,假手术组仅切除椎板,未造成SCI。按照体重将大鼠随机分为3组:实验组、模型组和假手术组,每组18只(3个时间段各6只)。造模后,实验组以右美托咪啶腹腔注射5μg·kg^(-1)。分别在造模后12,24,72 h,以酶联免疫吸附法检测组织内肿瘤坏死因子-α(TNF-α)和白细胞介素-1β(IL-1β)水平;在造模后第3天,以原位末端标记法观察SCI大鼠组织细胞凋亡情况。结果术后72 h,实验组、模型组和假手术组的IL-1β含量分别是(116. 57±13. 35),(250. 21±14. 29)和(16. 23±4. 71) pg·g^(-1);这3组的TNF-α含量分别是(58. 57±6. 31),(150. 29±8. 25)和(32. 94±2. 57)pg·g^(-1);这3组的凋亡荧光信号IOD值分别是1580. 33±103. 46,4190. 67±235. 03和261. 38±104. 54。模型组与假手术组比较,差异均有统计学意义(均P <0. 05);实验组与模型组比较,差异均有统计学意义(均P <0. 05)。结论右美托咪啶处理具有明显神经保护作用,其机制可能与减轻SCI大鼠组织炎性反应和抑制神经元细胞凋亡有关。

Objective To investigate the neuroprotection of dexmedetomidine on spinal cord injury(SCI)in rats and its mechanism.Methods The SCI rat model was built by violent collisions.Rats were randomly divided into three groups:experiment group,model group and sham-operated group,each group had 18 rats(six in each of three periods).The rats in experiment group were injected intraperitoneally with dexmedetomidine 5μg·kg-1.On 12,24,72 h after SCI,the levels of tumor necrosis factor-α(TNF-α)and interleukin-1β(IL-1β)in the SCI rat tissue were measured by enzyme-linked immunosorbent assay.On third day after the injury,cell apoptosis in SCI rat were detected by terminal-deoxynucleoitidyl transferase mediated nick end labeling staining.Results At 72 h after surgery,the IL-1βlevels of experimental group,model group and sham operation group were(116.57+13.35),(250.21+14.29),(16.23+4.71)pg·g-1,respectively;the TNF-αlevels in the three groups were(58.57±6.31),(150.29±8.25),(32.94±2.57)pg·g-1,respectively;the IOD values of apoptotic fluorescence signals in the three groups were 1580.33±103.46,4190.67±235.03,261.38±104.54,respectively.Comparison between the model group with the sham-operated group,the differences of the three factors were statistically significant(all P<0.05);comparisonbetween the experimental group with the model group,the differences of the three factors were statistically significant(all P<0.05).Conclusion Dexmedetomidine has neuroprotective effects for SCI rats,which may be related to its anti-inflammatory and anti-cell apoptosis effects.