锌对辣椒素致痛模型小鼠脊髓c-fos表达和动物行为学的影响

The effect of zinc on the c-fos expression in spinal cord and animal ethology of capsaicin inducing neuropathic pain mice

目的研究锌对辣椒素致痛模型小鼠脊髓c-fos表达和动物行为学的影响。方法 48只C57/BL6小鼠随机分为4组,采用足底注射辣椒素(0.5%,5μl)制备神经病理性疼痛(NPP)小鼠模型:对照组(Con)给予适锌饲料(锌30mg/kg/d)喂养2周后,右后足底注射溶剂(吐温80、酒精和生理盐水混合液);适锌喂养组(N-NPP)给予适锌饲料(锌30mg/kg/d)喂养2周后足底注射辣椒素;低锌喂养组(L-NPP)给予低锌饲料(锌0.85mg/kg/d)喂养2周后注射辣椒素;高锌喂养组(H-NPP)给予硫酸锌水溶液(227mg/L/d)喂养2周后注射辣椒素。应用原子吸收光谱技术、动物行为学观察、免疫组织化学和图像分析技术检测注射辣椒素后7d锌对脊髓cfos表达和动物行为学的影响。结果高锌喂养能显著增加血清和脊髓中锌的含量,使脊髓c-fos表达下调,机械痛阈增高,痛敏减弱(<0.01);而低锌喂养加重血清和脊髓的缺锌状态,脊髓c-fos表达上调,机械痛阈降低,痛敏增强(<0.01)。结论锌能抑制辣椒素致痛模型小鼠脊髓c-fos的表达,降低痛敏。

Objective To study the effect of zinc on the expression of c-fos in spinal cord and the animal ethology of capsaicin inducing neuropathic pain（NPP） mice. Methods 48 C57/BL6 mice were divided into 4 groups：control group（injected with solvent including Tween 80, alcohol and saline）, N-NPP group（capsaicin was injected into foot to build the NPP mice model, fed 30mg/kg/d of Zinc, injected with capsaicin for 2 weeks）, L-NPP group（fed low dose of zinc0.85mg/kg/d, injected with capsaicin for 2 weeks）, H-NPP group（fed high dose of zinc 227mg/L/d, injected with capsaicin for2 weeks）. Atomic absorption spectrum, animal ethology observation,immunohistochemistry and image analysis were used to determine the effect of zinc on the expression of c-fos in spinal cord and the animal ethology of model mice on the 7th day after NPP. Results High dose of zinc feeding could increase the zinc level in spinal cord and serum, the mechanical threshold, down-regulate the c-fos expression level（ 〈0.01）. Low dose of zinc feeding could decrease the zinc level in spinal cord and serum, the mechanical threshold, up-regulate the c-fos expression level（ 〈0.01）. Conclusion Zinc inhibits the c-fos expression in spinal cord and serum, decreases the hyperalgesia in capsaicin inducing NPP model mice.