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。

Abstract：Object Research studies have clearly shown that sea pyrimidine has definite antitumor activities. Its mechanis misrelated 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 [Ca²⁺]_i as [Ca²⁺]_ii was affected and changed by the influence of sea pyrimidine was observed by laser scanning confocal microscopy.Its influence on calciumpump of tumor cell membranew as determined by phosphorus assay. Results Sea pyrimidine can significantly increase the concent ration of [Ca²⁺]_i of tumor cells. The source of Ca²⁺ originated both from inward flow of extra cellular calciumcurrent and out ward flow of intracellular calciumre lease . Sea pyrimidine can decrease the activity of calcium pump of tumor cells . Conclusion Sea pyimidine can induce tumor cell apoptosis through increasing [Ca²⁺]_ilevel of tumor cell as resulted by openning the calcium path way , releasing calcium and decreasing the activity of calcium pump in tumor cells.

国家科委生命中心博士基金资助(项目号:96-901-06-10);中国优秀博士后基金资助(中博基[1999]17号);黑龙江省杰出青年基金资助(J9906);黑龙江省自然科学基金项目资助(项目号:D00-18)