锌对神经病理性疼痛小鼠脊髓bax表达和行为学的影响

The effect of zinc on the bax expression in spinal cord of neuropathic pain mice and ethology

目的研究锌对神经病理性疼痛(neuropathic pain,NPP)模型小鼠脊髓后角bax表达和动物行为学的影响。方法 24只C57/BL6小鼠随机分为4组,足底注射辣椒素(0.5%,5μl)制备NPP模型。对照组(喂养普通饲料,锌30mg/kg/d,2周后于足底注射溶剂吐温80、酒精和生理盐水混合液),适锌喂养组(N-NPP,饲喂普通饲料,锌30mg/kg/d,2周后制备NPP),低锌喂养组(L-NPP,饲喂低锌饲料,锌0.85mg/kg/d,2周后制备NPP),高锌喂养组(H-NPP,饲喂硫酸锌水溶液227mg/L/d,2周后制备NPP)。应用动物行为学观察、免疫组织化学和图像分析技术研究脊髓后角bax表达和动物行为学变化。结果高锌喂养能显著改善NPP后的痛觉过敏,提高机械痛阈,降低脊髓后角bax表达水平(<0.01);低锌喂养则加重行为学改变,使机械痛阈更低,脊髓后角bax表达水平更高(<0.01)。结论高锌能抑制NPP模型小鼠脊髓后角bax的表达,改善动物行为学。

Objective To study the effect of zinc on the bax protein expression in dorsal horn of spinal cord in capsaicin induced neuropathic pain（NPP） mice. Methods 24 C57/BL6 mice were randomly divided into 4 groups： NPP mice model（capsaicin induced）, control group（normally fed for 2 weeks and injected with Tween 80, alcohol and saline solvent）, N-NPP group（normal zinc）, L-NPP group（low-zinc foods for 2 weeks）, H-NPP group（high-zinc foods for 2 weeks）. Immunohistochemistry and image analysis were used to examine the bax protein expression in dorsal horn of spinal cord. Results High dose zinc improved the ethology and mechanical threshold, down-regulated the bax expression level in dorsal horn of spinal cord of NPP mice（P〈0.01）. Low dose zinc reduced the mechanical threshold, up-regulated the bax expression level（P〈0.01）. Conclusion High dose zinc inhibits the bax expression in dorsal horn of spinal cord and the ethology in capsaicin induced NPP model mice.