| AIM:1.To observe expression of NR2B, NF-κB and iNOS in the spinal cord in rat model of chronic constriction injury (CCI) of the sciatic nerve.2.To observe the effects of analgecine on hyperalgesia and expression of NR2B, NF-κB and iNOS in the spinal cord in rat model of the chronic constriction injury of the sciatic nerve.MERHODS:1.Fifty-six adult male Sprague-Dawley rats weighing180-220g were randomly divided into sham group (sham operation, n=8) and CCI group (CCI modeling, n=48). The mechanical withdrawal threshold (MWT) and paw withdrawal latency (PWL) of the hind paws were measured before CCI1day and on the1st,4th,7th,14th and21st day after surgery. The L4-6segment of the spinal cord was taken for determining the expression of NR2B, NF-κB and iNOS by RT-PCR and Western blotting.2. Ninty-six adult male Sprague-Dawley rats weighing180-220g were randomly divided into two groups:CCI group (CCI model, n=48) and A group (The block therapy of analgecine, n=48). After the MWT and PWL were measured, the L4-6segment of the spinal cord were taken for determination the expression of NR2B, NF-κB and iNOS using real time PCR and Western blot.RESULTS:1.On the1st,4th,7th,14th and21st day after surgery, the MWT and PWL in CCI group were obviously lower than those in sham group. The result of RT-PCR and WB showed that NR2B, NF-kB and iNOS increased significantly. Positive correlation was found between the mRNA expression of NR2B and iNOS (r=0.833, P<0.05), and between the mRNA expression of NF-κB and iNOS (r=0.842, P<0.05).2. Postoperative MWT and PWL of CCI group were obviously decreased than preoperative rats (n=8, P<0.01). The MWT and PWL of A group were increased significantly when compared to CCI group (n=8, P<0.05). NR2B, NF-κB and iNOS increased significantly when compared to preoperative rats (n=4, P<0.05). When A group was compared to CCI group, NR2B, NF-κB and iNOS decreased significantly (n=4, P<0.05). CONCLUSIONS:1.The generation and maintainance of hyperalgesia in sciatic nerve injured rats may attribute to the activation of NR2B and NF-κB concomitant increase in iNOS.2. The block therapy of analgecine can obviously improve the hyperalgesia of CCI rats. The change of expression of NR2B, NF-κB and iNOS in the spinal cord may result in this effect. |
