过量氟对大鼠肝细胞内钙水平和肝细胞凋亡的影响

The effect of excessive fluoride on ionized calcium level and apoptosis in liver cells

目的 研究在大鼠过量摄氟后体内对肝细胞中游离钙([Ca^(2+)]i)水平和肝细胞凋亡的影响。方法 应用饮水加入氟化钠进行大鼠染毒实验,采用Fura-2/AM荧光指示剂测定慢性氟中毒大鼠肝细胞内[Ca^(2+)]i浓度的变化,同时利用流式细胞术测定肝细胞凋亡率。结果 过量氟可刺激肝细胞内[Ca^(2+)]i浓度增高,常食(高钙饮食)投氟组与常食对照组相比差异显著(P<0.05),偏食低钙投氟组高于低钙对照组,差异显著(P<0.05);肝细胞凋亡率在正常饮食加氟组与对照组相比差异无显著性(P>0.05),低钙饮食加氟组肝细胞凋亡率明显增高,与低钙对照组相比,差异显著(P<0.05);相关分析显示,低钙饮食投氟组肝细胞内[Ca^(2+)]i浓度增高与细胞凋亡率有相关性趋势(r=0.576)。结论(1)过量氟所致的大鼠肝细胞内[Ca^(2+)]i持续增高对肝细胞凋亡有不同程度的影响,可能在氟骨症病理过程中起重要作用;(2)投氟伴随低钙可加重细胞内[Ca^(2+)]i超负荷和细胞凋亡,提示钙营养与氟中毒发病有着重要联系;(3)肝细胞内[Ca^(2+)]i增高与肝细胞凋亡率之间有无相关性有待于进一步研究证实。

Objective To study the effect of excessive fluoride on ionized calcium level and apoptosis in Jiver cells. Methods The toxic experiment of Wistar rats was taken by drinking water added with sodium fluoride , and then ionized calcium level and apoptosis in liver cells were determined by Fura - 2/AM fluoresce indicator and flow cytometry respectively. Results Excessive fluoride could stimulate [Ca2+ ]i of liver cells increased. There was a significant difference between fluoride exposed group (high calcium diet) and normal diet group( P < 0.05) .The same change was also seen between the group of low calcium + fluoride and the group of low calci-um( P < 0.05). The apoptotic rate of liver cells in the group of low calcium + fluoride was obviously augmented compared with the control group of low calcium ( P < 0.05) .The relative analysis showed that there was a correlative tendency between increased level of and apoptotic rate of liver cells in the group of low calcium + fluoride (r = 0.576) . Conclusions (1)The progressive increase of ionized calcium of liver cells by excessive fluoride may have effect on cycle and apoptosis of liver cells in various degree, that may play an important role in the chronic fluorosis pathogenesis.(2)Low calcium + fluoride could aggregate the over- load of [Ca2+ ]i and cells apoptosis, it suggested that calcium nutrient had important relation with the onset of fluorosis. (3)The correlation between the increasing level of with[ Ca 2+ ] i apoptotic rate in liver cells might be further certificated.