神经慢性挤压伤疼痛模型大鼠脊髓GABAA受体mRNA表达的变化

Changes of mRNA for GABAA receptor in spinal cord of rat in chronic constriction injury pain model

  • 摘要: 目的: 了解大鼠坐骨神经慢性挤压伤(chronic constriction injury,CCI)模型脊髓GABAA受体α2、γ2亚型mRNA表达的变化。方法: SD大鼠2 0只,5只为正常对照,15只做成CCI模型。用VonFrey细丝和CO2激光测定大鼠足爪的疼痛阈值变化,并于术后3d、7d和14d处死(n=5每组),取L4~5脊髓用RT PCR方法测定不同时点大鼠脊髓GABAA受体α2、γ2亚型mRNA的表达量。结果: CCI大鼠结扎侧在术后3d即开始出现机械感觉异常和痛觉过敏,7d、14d组逐渐加重(P<0.05)。与正常大鼠比较,CCI大鼠GABAA受体α2、γ2亚单位mRNA表达量于术后7d开始出现下降(P<0.05),且术后14d组进一步降低(P<0.01)。结论: CCI大鼠疼痛模型中脊髓GABAA受体α2、γ2亚单位的表达量明显下降,其在慢性神经性疼痛中发病机制中的确切作用尚待进一步研究。

     

    Abstract: Objective: To observe the changes of mRNA for GABAA receptor α2 and γ2 subunit in spinal cord of rat in chronic constrction injury(CCI)pain model. Methods: Five of twenty SD rats were selected as control and CCI was performed on theright sciatic nerves of other fifteen ones. The tests for mechanical allodynia and hyperalgsia of the plantar surface of both hind paws were done by Von Frey filaments and CO2 laser. CCI rats were killed at post- operative days 3(group PD3),7(group PD7) and 14(group PD14),each group has five rats.L4~5 spinal cords of CCI rats and control rats were dissected out and changes of mRNA for GABAA receptor α2 andγ2 subunit were measured by RT-PCR. Results: Mechanical allodynia and hyperalgsia were observed on the ligatedside of group PD3 post-operatively as compared with unligatedside.Mechanical allodynia and hyperalgsia on the ligatedside of group PD7 and group PD14were aggravatedas comparedwith group PD3. The mRNAexpression of group PD7 for GABAA receptorα2 andγ2subunit was significantly decreased as compared withcontrol, and decreased more in group PD14. Conclusion: mRNA for GABAA receptorα2 andγ2subunit is down-regulated in rat CCImodel. Its exact role on the pathogenesis of neuropathic pain deservesto be studied furthermore.

     

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