| Objective To investigate the effects of intrathecal injection of LV-Reelin-RNAi on the changes of pain behaviors and the expression of Reelin m RNA and protein in the spinal dorsal horn of neuropathic pain rats induced by chronic sciatic nerve constrictive injury(CCI). Methods One hundred and forty-four male SD rats(200-270g) with intrathecal catheter placement without motor dysfunction were randomly divided into 4 groups: sham group(n=36), CCI group(n=36), RNAi group(n=36) and empty vector group(n=36). Sham rats were just exposed the sciatic nerves without ligation, while rats in other groups were produced by loosely ligating a common sciatic nerve. Saline 15μl, saline 15μl, LV-Reelin-RNAi 5μl + saline 10μl or empty vector5μl + saline 10μl were respectively injected through intrathecal catheter on day 1 after operation. Paw withdrawal mechanical threshold(PWMT) and paw withdrawal thermal latency(PWTL) were tested on day 1 before operation and day 1, 4, 7, 10, 14, 17 and 21 after operation. QPCR, Western blot and IHC-P were used to detect the m RNA and protein level of Reelin in the spinal dorsal horn on day 7, 14, and 21 after the surgery. Results There is no significant difference of PWMT and PWTL in each experimental group at day 1 before operation(P>0.05). PWMT(P<0.05) and PWTL(P<0.05) were significantly decreased in rats submitted to CCI surgery. The expression of Reelin m RNA and protein in spinal cord are also downregulated after chronic constriction of the sciatic nerve. Compared to the CCI group, PWMT and PWTL in the RNAi group were further decreased. Correspond to pain behaviors changes, the expression of Reelin m RNA and protein obviously decreased after intrathecal injection of LV-Reelin-RNAi. Conversely, intrathecal injection of empty vector has no effects on the expression of Reelin and pain behaviors. Conclusions The expression of spinal Reelin is downregulated in neuropathic pain rats induced by chronic constriction of the sciatic nerve. Intrathecal injection of LV-Reelin-RNAi PWMT can further downregulated the expression of spinal Reelin and worse pain behaviors. Reelin may play a important role in the production and development of neuropathic pain induced by chronic sciatic nerve constriction injury. |
PDF Full Text Request