中文摘要：

目的：研究硒化乳酸菌胞外多糖对小鼠腹腔巨噬细胞、SGC7901胃癌细胞及海拉细胞（Helacells）内游离Ca2＋的影响。方法：分离制备小鼠腹腔巨噬细胞，利用Ca2＋荧光探针Fluo一3／AM及激光共聚显微镜测定加药后10min细胞内Ca2＋浓度的变化。结果：添加硒化多糖后，巨噬细胞内Ca2＋浓度缓慢升高，而胃癌细胞与Hela细胞NC2＋水平均有不同程度的下降。结论：通过对乳酸菌胞外多糖进行硒化修饰可增强其刺激巨噬细胞的能力，因而发挥其免疫功效。硒化多糖与肿瘤细胞表面受体结合后引起细胞Ca2＋内流的减少，提示硒化后的多糖可引起肿瘤细胞不同程度的细胞凋亡。

英文摘要：

Objective： The effect of Se-exopolysaccharide （EPS） from Lactococcus lactis subsp, lactis on intracellular free Ca2＋ levels in mouse macrophages cells, gastric cancer cells SGC7901 and Hela cells was studied. Methods： Cells labeled with Fluo-3/AM dye for t0 min were examined using laser confocal scanning microscope. Results： The intracellular Ca2＋ level in mouse macrophages increased in the presence of Se-EPS. On the other hand, Se-EPS could decrease the intracellular Ca2＋ levels both in gastric cancer cells SGC7901 and Hela cells. Conclusion： Se-EPS can activate macrophages, which may be related to Ca2＊ signal pathways. Se-rich EPS has gained the capacity to induceapoptosis in tumor cells.