青藤碱对神经病理性痛大鼠痛阈、脊髓氧化应激及背角神经元凋亡的影响

Effects of sinomenine on pain threshold, spinal oxidative stress and dorsal neurons apoptosis of neuropathologic pain rats

目的研究青藤碱对神经病理性痛大鼠痛阈、脊髓氧化应激及背角神经元凋亡的影响。方法将81只Wistar大鼠随机分为模型组、实验组及假手术组,各27只。模型组及实验组以坐骨神经慢性压迫损伤法构建神经病理性痛大鼠模型,假手术组仅游离坐骨神经但不结扎。建模后实验组腹腔注射盐酸青藤碱注射液40mg·kg-1·d-1,模型组及假手术组给予等量生理盐水,各组进行连续2周的药物干预。检测干预前及干预1,2周后大鼠机械痛阈(MWT)、热痛阈(TWL)及脊髓组织氧化应激指标水平;以细胞凋亡原位检测(TUNEL)法检测脊髓背角神经元凋亡情况。结果干预后2周,假手术组、模型组和实验组MWT分别为(15.26±2.98),(4.87±1.45),(8.38±1.35)g,TWL分别为(14.58±2.71),(6.20±1.71),(11.02±1.49)s;超氧化物歧化酶(SOD)分别为(186.47±19.12),(114.05±13.21),(167.24±14.89)U·mg-1,丙二醛(MDA)分别为(6.37±0.96),(15.76±2.46),(11.04±2.15)nmoL·mg-1;干预前及干预1,2周后,假手术组神经元凋亡比例分别为(2.41±1.03)%,(2.43±1.01)%,(2.47±1.05)%;模型组分别为(18.95±2.43)%,(19.41±2.57)%,(18.76±2.49)%;实验组分别为(18.99±2.38)%,(13.24±3.01)%,(5.12±2.03)%。与假手术组比,干预前及干预1、2周后模型组MWT、TWL及脊髓组织SOD含量降低,MDA含量及脊髓背角神经元凋亡比例升高(均P<0.05);与模型组比较,干预1,2周后实验组MWT、TWL及脊髓组织SOD含量升高,MDA含量及脊髓背角神经元凋亡比例降低(均P<0.05)。结论青藤碱在提高神经病理性痛大鼠痛阈方面效果显著,与对脊髓氧化应激反应及背角神经元凋亡的抑制相关。

Objective To explore the effect of sinomenine on pain threshold, spinal oxidative stress and dorsal neurons apoptosis of neuropathologic pain rats. Methods A total of 81 Wistar rats were randomly divided into model group, test group and sham-operation, 27 cases in each group. Model group and test group were built neuropathologic pain rat model by chronic compression injury of sciatic nerve, sham-operation group was only free sciatic nerve but no ligation. Test group was intraperitoneal injected 40 mg·kg-1·d-1 sinomenine hydrochloride injection after modeling, sham-operation group and model group were injected equal amount of 0.9% NaCl, each group was intervened for 2 weeks continuously. The mechanical paw withdrawal threshold(MWT),thermal paw withdrawal latency( TWL) and spinal oxidative stress indexes level of rats before intervention and 1,2 weeks after intervention were detected;the spinal dorsal neurons apoptosis was detected by Td T-mediated dUTP nick end labeling( TUNEL) method. Results 2 weeks after intervention,the MWT of sham-operation group,model group and test group were( 15. 26 ± 2. 98),( 4. 87 ± 1. 45),( 8. 38 ± 1. 35) g,TWL were( 14. 58 ± 2. 71),( 6. 20 ±1. 71),( 11. 02 ±1. 49) s;the superoxide dismutase( SOD) were( 186. 47 ± 19. 12),( 114. 05 ± 13. 21),( 167. 24 ±14. 89) U·mg-1,malondialdehyde( MDA) were( 6. 37 ± 0. 96),( 15. 76 ± 2. 46),( 11. 04 ± 2. 15)nmoL·mg-1. Before intervention and 1,2 weeks after intervention,the neurons apoptosis proportion in sham-operation group were( 2. 41 ± 1. 03)%,( 2. 43 ± 1. 01)%,( 2. 47 ± 1. 05)%;which in model group were( 18. 95 ±2. 43)%,( 19. 41 ± 2. 57)%,( 18. 76 ± 2. 49)%;which in test group were( 18. 99 ± 2. 38)%,( 13. 24 ±3. 01)%,( 5. 12 ± 2. 03)%. Compared with sham-operation group,the MWT,TWL and spinal tissue SOD content in model group decreased,MDA content and dorsal neurons apoptosis proportion increased before intervention and 1,2 weeks after intervention( all P < 0. 05);compared with model group,the MWT,TWL and spinal tissue SOD content in test group increased,MDA content and dorsal neurons apoptosis proportion decreased 1,2 weeks after intervention( all P < 0. 05). Conclusion Sinomenine can enhance the pain threshold of neuropathologic pain rat effectively,and the action mechanism maybe related to inhibit spinal oxidative stress response and dorsal neurons apoptosis.