| Objective: To investigate the correlation between intrathecal injection of Reelin recombinant protein and chronic sciatic nerve compression injury in rats with pain behavior and spinal cord Reelin signal pathway downstream protein Dab1 phosphorylation,astrocyte activation and expression of TNF-?.Methods: Male Sprague-Dawley rats with successful intrathecal catheterization,without motor dysfunction,weighing 250-400 g,aged 8-10 weeks,were enrolled in this study.The method of random digital table was divided into three groups : Sham group(sham-operation +intrathecal injection of PBS)(n=18)?CCI group(Sciatic nerve ligation+intrathecal injection of PBS)(n=18)and RELN group(Sciatic nerve ligation +intrathecal injection of Reelin recombinant protein)(n=18).The chronic pain model was established in RELN group and CCI group with 4.0 ligation of right sciatic nerve.The sciatic nerve was exposed but not ligated in Sham group.The RELN group received intrathecal injection of reelin recombinant protein 5 ?l(0.01?g/?l)on the 10 th day after CCI.The rest group was given 5 ?l PBS solution.The pain behavior of the right hind plantar of the rats was recorded 1 day before and 1?4?7?10?11?12?13?14?15?16?17?21day after CCI.These include paw withdrawal thermal latencyand mechanical foot contraction threshold paw withdrawal mechanical threshold.The rats were killed at 1 hour after administration and 3 days after administration.The dorsal horn of spinal cord was taken from the right side of lumbar enlargement to be used to detect the expression of Dab1 phosphorylated?GFAP and TNF-? by immunohistochemical Western blot method.Results:(1)There was no significant difference between the basic PWMT and PWTL in each group before operation.From the first day after operation,the expression of PWMT and PWTL in the CCI group was lower than that in the Sham group(P < 0.05),and lasted until the 21 st day.After intrathecal injection of Reelin recombinant protein,the PWMT and PWTL were increased significantly at 1 hour?1?2?3?4?5 day after intrathecal injection of the recombinant Reelin protein(P < 0.05).(2)The results of immunohistochemistry and Western blot showed that,compared with Sham group,the expression of Dab1 phosphorylation in spinal dorsal horn decreased significantly(P < 0.05)on the 10 th and 13 th day after CCI operation,and the expression of GFAP?TNF-? in the spinal dorsal horn was up-regulated.Compared with the CCI group,the expression of Dab1 phosphorylation in the dorsal horn of spinal cord was significantly increased in RELN group on the 1 hour and 3 day after intrathecal injection(P < 0.05),the expression of GFAP and TNF-? in the dorsal horn of spinal cord decreased significantly(P < 0.05).Conclusion: Intrathecal injection of Reelin recombinant protein can relieve neuropathic pain,and its mechanism may be related to the inhibition of the activation of astrocytes and the expression of TNF-? in the dorsal horn of spinal cord. |
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