海嘧啶对肿瘤细胞内[Ca^2＋]i的影响

目的　揭示海嘧啶诱导肿瘤细胞凋亡的机制。方法　采用激光扫描共聚焦技术观察海嘧啶对肿瘤细胞内Ca2 ]i 的影响及 Ca2 ]i 变化时 Ca2 的来源 ,采用定磷法测定海嘧啶对肿瘤细胞膜钙泵活性的影响。结果　海嘧啶可显著升高肿瘤细胞内 Ca2 ]i 的浓度 ,Ca2 ]i 升高时 ,Ca2 同时来源于细胞外钙内流和细胞内钙释放。海嘧啶可显著降低肿瘤细胞膜钙泵活性。结论　海嘧啶通过升高肿瘤细胞内 Ca2 ]i 的浓度 ,从而启动肿瘤细胞凋亡机制 ,诱导肿瘤细胞凋亡 ;海嘧啶升高肿瘤细胞内的作用是通过开放肿瘤细胞膜钙通道、引起肿瘤细胞内钙库释放、降低肿瘤细胞钙泵活性 3条途径达到的。

Influence of sea pyrimidine on [Ca2+]i in tumor cells

Object Research studies have clearly shown that sea pyrimidine has definite antitumor activities. Its mechanism is related to its inducement of tumor cell apoptosis. This is a further study to uncover the mechamism of its inducement of cell apoptosis. Methods The source of Ca 2 as Ca 2 ] i was affected and changed by the influence of sea pyrimidine was observed by laser scanning confocal microscopy. Its influence on calcium pump of tumor cell membrane was determined by phosphorus assay. Results Sea pyrimidine can significantly increase the concentration of Ca 2 ] i of tumor cells. The source of Ca 2 originated both from inward flow of extracellular calcium current and outward flow of intracellular calcium release. Sea pyrimidine can decrease the activity of calcium pump of tumor cells. Conclusion Sea pyrimidine can induce tumor cell apoptosis through increasing Ca 2 ] i level of tumor cell as resulted by openning the calcium pathway, releasing calcium and decreasing the activity of calcium pump in tumor cells.