神经病理性疼痛大鼠脊髓 NF-κB、NR2B和iNOS 的表达及意义

摘要

AIM:To observe the expression of nuclear factor-kappa B ( NF-κB) , N-methyl-D-aspartic acid re-ceptor 2B (NR2B) and inducible nitric oxide synthase (iNOS) in the spinal cord in a rat model of chronic constriction in-jury (CCI) of the sciatic nerve.METHODS:Fifty-six adult male Sprague-Dawley rats weighing 180~220 g were random-ly divided into sham group (n=8) and CCI group (n=48).The mechanical withdrawal threshold (MWT) and paw with-drawal latency (PWL) of the hind paws were measured 1 d before CCI and 1 d, 4 d, 7 d, 14 d and 21 d after surgery.The L4~L6 segment of the spinal cord was taken for determining the expression of NF-κB, NR2B and iNOS by RT-PCR and Western blotting.RESULTS:At 1 d, 4 d, 7 d, 14 d and 21 d after surgery, the MWT and PWL in CCI group were obviously lower than those in sham group .The expression of NF-κB, NR2B and iNOS at mRNA and protein levels in-creased significantly.Positive correlations were found between the mRNA expression of NF-κB and iNOS (r=0.842, P<0.05), and between the mRNA expression of NR2B and iNOS (r=0.833, P<0.05).CONCLUSION:The generation and maintenance of hyperalgesia in sciatic nerve injury rats may attribute to the activation of NF -κB and NR2B and concom-itant increase in iNOS .%目的：探讨坐骨神经慢性压迫性损伤（CCI）大鼠脊髓核因子κB（NF-κB）、N-甲基D-天冬氨酸受体2B亚基（NR2B）和诱导型一氧化氮合酶（iNOS）的表达及意义。方法：56只180～220 g雄性SD大鼠随机分为2组：sham组（n＝8）和CCI组（n＝48）。于术前1 d、术后1 d、4 d、7 d、14 d和21 d测定机械缩爪阈值（MWT）和热刺激缩爪潜伏期（PWL）后处死，取L4～L6脊髓，采用RT-PCR和Western blotting 检测脊髓NF-κB、NR2B和iNOS的表达。结果：CCI组MWT及PWL值较sham组明显降低（P＜0.05， n＝8）。 RT-PCR和Western blotting 结果显示CCI组术后脊髓NF-κB、NR2B和iNOS明显高于术前（ P＜0.05， n＝4）。 iNOS mRNA与NF-κB mRNA和NR2B mRNA的表达呈显著正相关（ r＝0.842， P＜0.05；r＝0.833， P＜0.05）。结论：CCI大鼠痛觉过敏的产生和维持可能与脊髓NF-κB和NR2B活化并上调iNOS表达水平有关。