吗啡对大鼠海马星形胶质细胞[Ca^(2+)]i的影响

Effect of morphine on the changes of intracellular free calcium in cultured hippocampal astrocytes in rat

目的 研究吗啡对大鼠海马星形胶质细胞 [Ca2 + ]i的影响 ,探索吗啡对星形胶质细胞的作用效应。方法 运用荧光探针Fluo 4,利用激光共聚焦显微镜研究培养纯化大鼠海马星形胶质细胞 [Ca2 + ]i的变化。结果 经 0 .5、1、2、10μmol L浓度的吗啡短期处理 3d后 ,细胞内Ca2 + 浓度与正常细胞比较差异无显著性 (P >0 .0 5 ) ;吗啡急性作用于正常星形胶质细胞后 ,[Ca2 + ]i呈单峰样升高 ;而作用于吗啡处理后的细胞 ,作用浓度需高于处理浓度出现 [Ca2 + ]i呈单峰样升高的现象 ,纳络酮可阻断上述效应 ,NMDA受体阻断剂MK 80 1则不能。结论 星形胶质细胞 [Ca2 + ]i对吗啡的反应性变化可能参与吗啡耐受的形成。

Objective To investigate the effects of morphine on the changes of intracellular free calcium in cultured hippocampal astrocytes and the mechanisms of morphine. Methods Changes of [Ca 2+ ]i induced by morphine in cultured and purified hippocampal astrocytes were detected with laser scanning confocal microscope (LSCM) by using Ca 2+ sensitive dye fluo 4 as a calcium fluorescent probe. Results No significant difference of the intracellular free Ca 2+ of astrocytes was found 3 days after treatment with 0.5 μmol/L, 1 μmol/L, 2 μmol/L and 10 μmol/L morphine, respectively ( P >0.05). Spike of [Ca 2+ ]i of astrocytes was induced by acute morphine administration, but the spike of [Ca 2+ ]i of astrocytes pretreated with morphine could be induced only by higher concentration of morphine. The [Ca 2+ ]i response of astrocytes to morphine could be blocked by naloxone but not by MK 801(NMDA receptor antagonist). Conclusion The response of [Ca 2+ ]i in morphine induced astrocytes may play an important role in morphine tolerance.