氟对小鼠神经细胞内游离钙的影响

Effect of fluoride on the intracellular Ca^2＋ in neurons of mice

目的 观察氟对小鼠神经细胞内游离钙（Ca^2＋）的影响，为探讨氟中毒的发生机制提供实验依据。方法 ①采用细胞培养方法，体外培养小鼠神经细胞。根据加氟剂量（NaF，0、5．0、10．0、15．0、20．0、40．0mg／L）不同分为6组，在培养第15天，收集各组细胞，激光扫描共聚焦显微镜记录细胞内Ca^2＋荧光图像；②出生后7d小鼠，按腹腔注射不同剂量的氟溶液（0、0．7、2．8、11．2mg／kg）分为4组，于注射后8h处死小鼠，收集脑细胞，制备细胞悬液，记录细胞内Ca^2＋荧光图像。结果 体外培养加氟（≥5．0mg／L）和体内腹腔注射氟溶液（≥0．7mg／kg）均可导致神经细胞内Ca^2＋增加，组间比较差异有统计学意义（F=191．20、93．83，P〈0．01）；各加氟组细胞内Ca^2＋水平与对照组比较，差异均有统计学意义（P〈0．01）。结论 氟诱导神经细胞内Ca^2＋增加，且随着加氟剂量的增加，细胞内Ca^2＋水平也增加，二者呈剂量效应关系。

Objective To observe neurotoxicity caused by fluoride in order to provide an experimental basis for studying the mechanism of fluorosis. Methods ①Neuron were cultured at different doses of fluoride （0,5.0,10.0,15.0,20.0,40.0 mg/L）. Neurons were recollected on the 15th day of cell culture to observe morphology. Ca^2＋ in neuron was inspected with confocal laser scanning microscopy; ② Wistar newborn rats were injected intraperitoneally with different doses of fluoride （0,0.7,2.8,11.2 mg/kg）; 8 hours later, rats were killed for collecting brain cells and making cell suspension. Ca^2＋ in neurons were then inspected with confocal laser scanning microscopy. Results In vitro culture in Flouride medium（≥5.0 mg/L）or introperitoneal injection of fluoride （≥10.7 mg/kg） could induce the intracellular Ca^2＋ to increase in mice with fluorosis, the difference being significant between groupos （F= 191.20,93.83, P 〈 0.01）. Conclusion Flouride induces intracellular Ca^2＋ to increase in a dose-dependent manner.