ERK-TRPV4途径参与大鼠背根神经节持续受压后痛觉敏感的脊髓中枢敏化机制的研究

关键词：背根神经节持续受压  痛觉敏感  脊髓  中枢敏化

Keywords:chronic compression of dorsal root ganglion  allodynia  spinal cord  central sensitization

摘要：

      摘要 目的：探讨ERK-TRPV4途径参与大鼠背根神经节持续受压(CCD)后痛觉敏感的脊髓中枢敏化的机制。 方法：选取SPF级雄性Wistar大鼠共42只，随机分为空白对照组6只，CCD手术组36只（包括术后2d、4d、7d、10d和14d，每组6只，以及免疫荧光组6只）。利用免疫共沉淀检测正常大鼠脊髓背角中ERK与TRPV4的相互联系。利用免疫组织化学染色法，观察ERK与TRPV4的分布情况。制备CCD模型，利用western blot技术检测空白对照组及术后2d，4d，7d，10d及14d，手术侧及对侧脊髓背角ERK和TRPV4蛋白表达的变化。利用免疫荧光技术观察术后4d脊髓背角中ERK和TRPV4阳性细胞数目、神经元的形态及阳性神经元比率的变化。 结果：CCD术后第2天至第10天，手术侧脊髓背角中ERK及TRPV4表达明显升高（P<0.01）。同时，手术侧脊髓背角中ERK和TRPV4阳性细胞数目、共同阳性表达细胞数及阳性神经元细胞比率均高于非手术侧（P<0.01）。脊髓背角阳性神经元分布于灰质第Ⅰ至Ⅳ层，手术侧的神经元树突棘生成增加，胞体增大。 结论：ERK-TRPV4通路参与了CCD后痛觉敏感的脊髓中枢敏化机制。

Abstract:

      Abstract Objective: To investigate the role of ERK-TRPV4 pathway in central sensitization mechanism of the spinal cord after chronic compression of the dorsal root ganglion (CCD) in rats. Method:Forty-two SPF male Wistar rats were randomly divided into control group (6 rats) and CCD group (36 rats， including 6 rats in each subgroup:2 days， 4 days， 7 days， 10 days and 14 days after operation respectively， and 6 rats in fluorescence subgroup). Immunoprecipitation was used to observe the interaction between ERK and TRPV4 in the spinal dorsal horn of normal rats. Immunohistochemical staining was used to observe the distribution of ERK and TRPV4. After CCD models were established，western blot was used to detect the ERK and TRPV4 protein expression of control group and CCD group in the dorsal horn of the spinal cord on the operative side and contralateral side. Four days after the operation， the number of ERK and TRPV4 positive cells， morphological changes of neurons and the ratio of positive neurons in the dorsal horn of the spinal cord were observed and compared. Result: From day 2 to day 10 after CCD， ERK and TRPV4 expression in spinal dorsal horn were significantly increased (P<0.01). The number of ERK and TRPV4 positive cells， the number of common positive expression cells and the ratio of positive neurons in the dorsal horn of the spinal cord on the operative side were all higher than those on the non-operative side (P<0.01). The positive neurons of spinal dorsal horn were distributed in layers Ⅰ to Ⅳ of gray matter， and the formation of dendritic spines and cell bodies on the surgical side were increased. Conclusion: ERK-TRPV4 pathway is involved in the sensitization mechanism of spinal cord after CCD.