锌对辣椒素致痛模型小鼠脊髓磷酸化ERK表达和热痛阈的影响

目的 研究锌对辣椒素致痛模型小鼠脊髓磷酸化（p）的细胞外信号调节激酶（extracellularsignal-regulate kinase,ERK）表达和热痛阈的影响。方法 72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（neuropathic pain,NPP）动物模型：对照组（Con）锌饲料30 mg/（kg·d）喂养2周后足底注射溶剂（吐温80、酒精和0.9%氯化钠注射液混合液）;N-NPP组锌饲料30 mg/（kg·d）喂养2周后给予足底注射辣椒素,L-NPP组锌饲料0.85 mg/（kg·d）喂养2周后注射辣椒素,H-NPP组硫酸锌水溶液227 mg/（L·d）喂养2周后注射辣椒素。应用动物行为学检测、免疫组织化学、免疫印迹和图像分析技术检测注射后7 d锌对动物行为学以及脊髓pERK表达的影响。结果 高锌喂养能显著降低脊髓pERK的表达,降低痛敏,使热痛阈增高（P〈0.01）;而低锌喂养能增加脊髓pERK的表达,增加痛敏,使热痛阈降低（P〈0.01）。结论 锌能抑制辣椒素致痛模型小鼠脊髓pERK的表达和热痛觉过敏。

Effect of zinc on the phosphorylative ERK expression in capsaicin induced neuropathic pain in mice spinal cord and hot pain threshold

Objective To observe the effect of zinc on the expression of phosphorylative extracellularsignal-regulate kinase （pERK） in spinal cord and the hot pain threshold of capsaicin induced neuropathic pain （NPP） in model rats. Methods Seventy two C57/ BL6 rats were randomly divided into 4 groups and capsaicin （0.5%, 5 p, 1） was injected in feet of NPP rats to build the model. Control group： normal （zinc, 30 mg/（kg ~ d）） fed rats injected with solvent （Tween 80, alcohol and 0.9% sodium chloride solution）; N-NPP group： normal fed rats were injected with capsaicin after 2 weeks; L-NPP group： low-zinc （0.85 mg/（kg ~ d）） fed rats were injected with capsaicin after 2 weeks; H-NPP group： high-zinc （227mg/（L. d）） fed rats were injected with capsaicin after 2 weeks. Animal ethology observation, immunohistochemistry, immune blotting and image analysis were used to test the effect of zinc on the expression of pERK in model mice spinal cord and the hot pain threshold during seven days after injection. Results High-zinc feed could down-regulate the pERK expression, improve the hot pain threshold （P 〈 0.01）, while low-zinc feed can up-regulate the pERK expression, reduce the hot pain threshold （P 〈 0.01）. Conclusion Zinc can inhibit the pERK expression in spinal cord and the hot pain threshold of capsaicin induced NPP in model rats.