川芎嗪通过抑制脊髓小胶质细胞活化缓解吗啡耐受

Tetramethylpyrazine attenuates morphine tolerance through suppressing spinal microglia activation in mice

探讨川芎嗪对脊髓小胶质细胞活化和慢性吗啡耐受的影响并考察其作用机制。运用水浴甩尾法检测慢性吗啡耐受小鼠甩尾痛阈;免疫荧光法检测小鼠脊髓水平小胶质细胞标记分子(ionized calcium binding adapter molecule 1,IBA1)的变化情况;Western blot法检测p38 MAPK(mitogen-activated protein kinase,MAPK)磷酸化水平的改变,以及RT-PCR法检测川芎嗪对慢性吗啡耐受过程中白细胞介素-1β(IL-1β)和肿瘤坏死因子-α(TNF-α)mRNA表达水平的影响。实验结果发现,川芎嗪(15,30,60 mg/kg)能够剂量依赖性地抑制吗啡引起的脊髓IBA-1、p-p38 MAPK、p38、TNF-α和IL-1β水平的升高,改善慢性吗啡耐受。研究结果表明,川芎嗪能显著改善慢性吗啡耐受,其机制可能与抑制小胶质细胞p38 MAPK信号通路有关。

The aim of the present study was to investigate the effects and possible mechanism of tetrameth- ylpyrazine （TMP） on morphine-induced microglia activation and tolerance. The antinociception and morphine tol- erance were assessed in mice using hot-water tail flick test. IBA-1 （ ionized calcium binding adapter molecule 1）, the marker of microglia, was detected by immumofluorescence method. The expression of p-p38 MAPK and total p38 MAPK （mitogen-activated protein kinase, MAPK） was analyzed by Western blot; real-time polymerase chain reaction （RT-PCR） was used to detect the expression level of tumor necrosis factor-α （TNF-α） and interleukin- 1β （ IL-1β）. Results showed that TMP （ 15, 30, 60 mg/kg, ip） inhibited morphine-induced up-regulation of IBA- 1, p-p38, TNF-α and IL-1β in a dose-dependent manner, yet with no effect on the expression of total p38 MAPK. In conclusion, TMP significantly inhibited the activation of microglia evoked by morphine via p38 MAPK signaling pathway, thus attenuating morphine antinociception tolerance.