大鼠背根神经节持续受压后脊髓背角TRPV4蛋白表达及分布的变化

关键词：脊髓背角  TRPV4  病理性神经痛

Keywords:spinal dorsal horn  TRPV4  neuropathic pain

摘要：

      摘要 目的：探讨大鼠背根神经节持续受压（chronic compression of the dorsal root ganglion，CCD）后瞬时感受器电位离子通道香草素亚族受体4（transient receptor potential vanilloid 4，TRPV4）在脊髓背角中的蛋白表达及分布规律。 方法：选取清洁级雄性Wistar大鼠30只，按随机数字表法分组：空白对照组5只，手术组25只（术后4天、7天、14天、28天各5只；免疫荧光组5只） 。制备大鼠背根神经节持续受压模型，于术后4天，7天，14天及28天，测量机械刺激缩爪反应痛阈，观察机械痛阈的变化；利用western blot技术检测空白对照组及术后4天，7天，14天及28天，手术侧及对侧脊髓背角TRPV4蛋白表达的变化；利用免疫荧光技术检测术后4天，手术侧与对侧脊髓背角TRPV4阳性细胞分布。 结果：大鼠背根神经节持续受压后4—14天，机械痛阈值明显下降（P<0.001）；术后4—7天，手术侧脊髓背角TRPV4表达升高（P<0.01），对侧无明显变化；手术侧脊髓背角内TRPV4阳性细胞数目高于对侧（P=0.0008）。 结论：大鼠背根神经节持续受压后，机械痛阈下降的同时，手术侧脊髓背角内TRPV4蛋白表达上调及阳性数目增多，TRPV4可能参与CCD后病理性神经痛的中枢敏化机制。

Abstract:

      Abstract Objective: To investigate the alternation of transient receptor potential vanilloid 4 (TRPV4) protein expression and distribution in spinal dorsal horn in chronic compression of the dorsal root ganglion(CCD) model of rats. Method: A total of 30 Wistar rats were randomly divided into a control group （5 rats) and operated group (4,7,14 and 28 days after operation, 5 rats in each group;and 5 rats in immunofluorescence group). Chronic compression of dorsal root ganglion (DRG) model was established. At 4, 7, 14 and 28 days after CCD operation, the paw withdrawal mechanical threshold was tested, then the expression of TRPV4 in ipsilateral and contralateral spinal dorsal horn was tested. The distribution of TRPV4 positive neurons in ipsilateral and contralateral spinal dorsal horn were detected at 4 days after operation. Result: 4—14 days after CCD operation, the paw withdrawal mechanical threshold decreased significantly(P<0.001). 4—7 days after CCD operation, the expression of TRPV4 in ipsilateral spinal dorsal horn was up-regulated (P<0.01), while there was no significant change of TRPV4 in contralateral spinal dorsal horn. At 4 days after CCD operation, the number of TRPV4 positive neurons in ipsilateral spinal dorsal horn was significantly more than that in contralateral spinal dorsal horn (P=0.0008). Conclusion: After CCD operation, the paw withdrawal mechanical threshold decreased, the expression of TRPV4 in ipsilateral spinal dorsal horn was up-regulated and the number of TRPV4 positive neurons increased. TRPV4 may take part in the central sensitization mechanism of neuropathic pain of CCD rats.