两种有机磷酸酯对人成神经细胞瘤细胞生长与钙摄取的影响

Effects of organophosphates on cell proliferation and ^(45)Ca uptake of neuroblastoma SH-SY5 Y cells

目的 探讨具有迟发性神经毒性的有机磷酸酯 (organophosphates,OPs)对人成神经细胞瘤细胞SH SY5Y的毒性作用。方法 采用四甲基偶氮唑蓝 (MTT)比色法测定SH SY5Y细胞活力 ;用培养的SH SY5Y细胞与45CaCl2 和磷酸三邻甲苯酯 (tri o cresylphosphate ,TOCP)或甲胺磷共育后 ,洗脱 ,裂解 ,经液闪仪计数测定细胞对钙的摄取情况。结果 甲胺磷在较低浓度 (7× 10 -7～ 7× 10 -6mol/L)时可刺激SH SY5Y细胞的生长 ,在 7× 10 -7mol/L浓度时细胞的增长比对照增加了 2 8% ,而在高浓度 (7× 10 -4～ 7× 10 -3mol/L)时抑制细胞生长 ,在 7× 10 -3 mol/L时的抑制率为 6 2 % ;但TOCP只在高浓度 (7× 10 -3 mol/L)时才对细胞的生长有抑制作用 (抑制率为 34% )。TOCP在几乎所有的测试浓度下都对SH SY5Y细胞的钙摄取量有影响 :在低浓度 (1× 10 -9～ 1× 10 -7mol/L)时刺激细胞的钙摄取 ,细胞的钙摄取量最高增加 2 4 1% ,但在高浓度 (1× 10 -6～ 1× 10 -4mol/L)时抑制细胞的钙摄取 ,最高的抑制率达 5 5 %。结论 OPs的神经毒性可能涉及阻遏神经细胞生长和干扰细胞钙平衡。

Objective To explore the mechamism of cytotoxic effects of the organophosphates(OPs) with delayed neurotoxicity on human neuroblastoma cells. Methods The proliferation of neuroblastoma SH-SY5Y cells was determined by MTT spectrometry. 45 Ca uptake was determined by adding 45 CaCl_2 and tri- o -cresyl phosphate(TOCP) or methamidophos into the cultured medium for the SH-SY5Y cells.The cells were incubated and then lysed and finally counted in a Beckman LS 6000 liquid scintillation spectrometer. Results Methamidophos stimulated the cell proliferation of SH-SY5Y at its lower concentrations (7×10 -7 mol/L to 7×10 -6 mol/L),with an increase by 28% at 7×10 -7 mol/L;however,it inhibited the proliferation at higher ones(7×10 -4 mol/L to 7×10 -3 mol/L) with 62% inhibition at 7×10 -3 mol/L.TOCP only inhibited the cell proliferation at high concentration(with 34% inhibition at 7×10 -3 mol/L) and markedly inhibited calcium uptake of the cells up to 55% at higher concentrations(1×10 -6 mol/L to 1×10 -4 mol/L);while the uptake was stimulated by OPs up to 241% of increase at lower concentrations(1×10 -9 mol/L to 1×10 -7 mol/L). Conclusion The interference of growth in nerve cells and disturbance of calcium homeostasis may be involved in the mechanisms of neurotoxicity of OPs.