Over-expression of P2X7 receptors in spinal glial cells contributes to the development of chronic postsurgical pain induced by skin/muscle incision and retraction (SMIR) in rats.

Over-expression of P2X7 receptors in spinal glial cells contributes to the development of chronic postsurgical pain induced by skin/muscle incision and retraction (SMIR) in rats. Exp Neurol. 2014 Sep 18; Authors: Ying YL, Wei XH, Xu XB, She SZ, Zhou LJ, Lv J, Li D, Zheng B, Liu XG Abstract Many patients suffer from chronic postsurgical pain (CPSP) following surgery, and the underlying mechanisms are poorly understood. In the present work, with use of skin/muscle incision and retraction (SMIR) model, the role of P2X7 receptors (P2X7Rs) in spinal glial cells in the development of CPSP was evaluated. Consistence with previous reports, we found that SMIR decreased the ipsilateral 50% paw withdrawal threshold (PWT), lasting for at least 2weeks. No injury was done to L3 dorsal root ganglia (DRG) neurons and no axonal or Schwann cell damage at the retraction site in the saphenous nerve was observed 7days after SMIR. The results of immunofluorescence showed that both microglia and astrocytes were activated in spinal dorsal horn following SMIR. In addition, both P2X7Rs and tumor necrosis factor-alpha (TNF-α) were up-regulated following SMIR. Double immunofluorescence staining revealed that the up-regulated P2X7Rs immunoreactivity was mainly located in microglia, and to a lesser extent in astrocytes, but not in neurons. Intrathecal delivery of specific P2X7Rs antagonist BBG (10μM in 10μl volume) or A438079 (10μM in 10μl volume), started 3...
Source: Experimental Neurology - Category: Neurology Authors: Tags: Exp Neurol Source Type: research