Graduate School of Human and Natural Environment Sciences, The University of Tokushima, Tokushima 770, Japan.
Environ Toxicol Pharmacol. 1997 Sep;3(4):237-44. doi: 10.1016/s1382-6689(97)00017-3.
To study the cellular basis of the neurotoxicity of methylmercury, the effects of methylmercury on dissociated rat cerebellar neurons were examined using a flow cytometer, a confocal laser microscope and three fluorescent dyes, fluo-3 for monitoring the changes in intracellular Ca(2+) concentration (Ca(2+)) and for detecting live neurons, ethidium for assessing the neurons that are dead or have compromised membranes, and 5-chloromethylfluorescein (CMF) for estimating the cellular content of nonprotein thiols. Methylmercury at concentrations of 1 μM or greater increased the Ca(2+) of almost all neurons. Prolonged exposure to methylmercury (3 and 10 μM) produced a further increase in Ca(2+), in association with compromising membranes in some neurons. Thereafter, methylmercury induced blebs on membranes of some neurons with increased Ca(2+). Methylmercury at concentrations of 0.3 μM or greater dose-dependently decreased the cellular content of nonprotein thiols. Results suggest that methylmercury may induce the loss of membrane integrity through destabilized Ca(2+) homeostasis and oxidative stress in mammalian brain neurons.
为了研究甲基汞的神经毒性的细胞基础，使用流式细胞仪、共聚焦激光显微镜和三种荧光染料研究了甲基汞对分离的大鼠小脑神经元的影响，Fluo-3 用于监测细胞内 Ca(2+)浓度 (Ca(2+)) 的变化并检测活神经元，碘化丙啶用于评估死亡或膜受损的神经元，5-氯甲基荧光素 (CMF) 用于估计非蛋白巯基的细胞含量。浓度为 1 μM 或更高的甲基汞几乎增加了所有神经元的 Ca(2+)。长时间暴露于甲基汞（3 和 10 μM）会进一步增加 Ca(2+)，同时一些神经元的膜受损。此后，甲基汞诱导一些 Ca(2+) 升高的神经元的膜泡。浓度为 0.3 μM 或更高的甲基汞剂量依赖性地降低了非蛋白巯基的细胞含量。结果表明，甲基汞可能通过破坏 Ca(2+) 动态平衡和氧化应激诱导哺乳动物脑神经元膜完整性丧失。
