Effect Of Intrathecal Curcumine On The Expression Of NMDA Receptor NR2B Subtype In Spinal Doral Horn In CCI Rats

Objective:To observe the effects of intrathecal curcumine on the expression of NMDA receptor NR2B subtype in spinal doral horn in CCI rats and disscuss its mechanism.Methods:Seventy-five male SD rats, successfully inserted intrathecal cather, were randomly devided into 5 groups(n=15):①Control group(treated with CCI);②Sham operation group;③Solvent contrast group(treated with CCI);④urcumin treated group(Cur100,Cur500),treated with CCI,intrathecal injected with Curcumin 100ug/10ul,500ug/10ul for 4 days after operation third day. Paw withdraw thermal latency(PWTL) and paw withdraw mechanical threshold(PWMT) were measured on 1d before CCI and 1d,3d,5d,,7d,9d, 11d,14d after CCI.Rats were killed on 3 th,7 th,14th day after CCI respectively (n=5)and take the L4-5 spinal to observe the expression of NMDA2bR in spinal doral horn which were assessed by immunohistochemical analysis.Result 1.PWMT and PWTL:Before the operation,the fundamental threshold of paw withdraw mechanical (PWMT) and thermal latency(PWTL) in each group were almost the same(P>0.05).The PWMT and PWTL in Sham group were almost the same during the research(P>0.05).The PWMT and PWTL in SC group and Con group were almost the same during the research(P>0.05).Dring the first 3 days, the PWMT and PWTL in each group were lower than Sham group(P<0.05).At the 5th day,the PWMT and PWTL in Cur100 group and Cur500 group rised up,higher than Con group and SC group (P<0.05),but lower than group Sham (P<0.05).the PWMT and PWTL in Cur500 group were higher than Cur100 group (P<0.05).At the 7th day,the PWMT and PWTL in Cur100 group and Cur500 group rase to the highest point, but lower than group Sham (P<0.05).the PWMT and PWTL in SC group and Con group dropped to the lowest point(PWMT 7.58±0.17g,PWTL 6.14±0.29s).At the 11th day,the PWMT and PWTL in CurlOO group and Cur500 group dropped significantly,but higher than Con group and SC group (P<0.05).the PWMT and PWTL in Cur500 group were higher than Cur100 group (P<0.05).At the 14th day,the PWMT and PWTL in CurlOO group were almost the same as Con group and SC group(P>0.05).,but Cur500 group were higher than Con group and SC group (P<0.05).Immunohistochemistry The number of NMDAR2B masculine cell in group Sham were almost the same during the research(P>0.05),group Con and group Cur were higher than group Sham (P<0.05).The number of NMDAR2B masculine cell in SC group and Con group were almost the same uring the research(P>0.05). At the 7th day,the number of NMDAR2B masculine cell in CurlOO group and Cur500 group were lower than group Con(P<0.05),and Cur500 group were lower than CurlOO group(P<0.05).At the 14th day,the number of NMDAR2B masculine cell in Cur500 group were lower than group Con(P<0.05)Conclusion 1.In the model of CCI rats, intrathecal inject curcumine showed dose dependent analgesic effect,and could last for a week after discontinuation.2.The mechanism of curcumine relieve the pain of CCI rats was related with the decrease of NMDA2B in spinal cord.