锌对神经病理性疼痛模型小鼠脊髓磷酸化cAMP反应元件结合蛋白表达的影响

摘要

目的：研究锌对神经病理性疼痛(neuropathic pain，NPP)模型小鼠脊髓磷酸化(phosphoryltion，p)的cAMP反应元件结合蛋白(camp response-element binding protein，CREB)表达的影响。方法72只C57/BL6小鼠随机分为4组，正常喂养的NPP组锌饲料30 mg/(kg·d)喂养2周，低锌喂养的NPP组锌饲料0.85 mg/(kg·d)喂养2周，高锌喂养的NPP组用硫酸锌水溶液227 mg/(L·d)喂养2周。采用足底注射辣椒素(0.5%5μl)制备NPP模型：对照组锌饲料30 mg/(kg·d)喂养2周后足底注射溶剂。应用原子吸收光谱、免疫组织化学、免疫印迹和图像分析技术检测术后7 d锌对脊髓pCREB表达的影响。结果高锌喂养能显著增加血清和脊髓中锌的含量，脊髓pCREB表达下调(P＜0.01)；而低锌喂养加重血清和脊髓的缺锌状况，脊髓pCREB表达上调(P＜0.01)。结论锌能抑制NPP模型小鼠脊髓pCREB的表达。%Objective To study the effect of zinc on expression of phosphorylated camp response-element binding protein (pCREB) in spinal cord of a mouse neuropathic pain (NPP) model.Methods Seventy-two C57/BL6 mice were divided into normal NPP group, low zinc NPP group, high zinc NPP group, and control group (18 in each group) and fed with 30 mg zinc (kg·d), 0.85 mg zinc (kg·d), 227 mg zinc sulfate water solution (L·d), and 30 mg forage (kg·d) for 2 weeks, respectively. Seven days after a mouse NPP model was established by injecting 0.5% 5 µl capsaicin into the planta (control group: injected solvent), effect of zinc on expression of pCREB in spinal cord of mice was detected by atomic absorption spectrum, immunohistochemistry, immunoblotting, and image analysis, respectively.Results The zinc level in spinal cord and serum were all significantly higher while the expression level of pCREB in spinal cord was significantly lower in high zinc NPP group than in other groups (P<0.01). The zinc level in spinal cord and serum were all significantly lower while the expression level of pCREB in spinal cord was significantly higher in low zinc NPP group than in other groups (P<0.01).Conclusion Zinc can inhibit the expression of pCREB in spinal cord of mouse NPP model.