巨噬细胞激活及钙作用的初步研究

STUDIES ON MACROPHAGE ACTIVATION AND CALCIUM

经TG诱发的小鼠腹腔渗出液的巨噬细胞及人的巨噬细胞样细胞株U937受PAF(100ng ml).Zymosan A(0.25mg ml).Can A(50μg ml)LPS(1μg ml)等作用后.能引起胞内游离Ca^(2-)浓度的增加,巨噬细胞内酸性磷酸酶增多,细胞骨架更为舒展、丰满.胞内游离Ca^(2-)的增加是由于胞内钙库的释放与胞外钙的内流.上述困子作用后,可使巨噬细胞产生呼吸爆发.其中.Zymosan A的作用尤为强烈.同时还出现胞膜流动性的降低、当胞外环境中有Ca^(2-)时.可增强巨噬细胞的呼吸爆发.以上提示:在巨噬细胞的激活中Ca^(2-)具有重要的作用.

Early events in the activation of macrophages were studied in a human macrophage -like cell line U937 and peritoneal macrophages from female Balb c mice. Peritoneal macrophages were successfully primed by a culture medium contained TG for microorganism. In the meantime, method for measuring [Ca2+] was established in our laboratory, using Fura -2 AM as a fluorescence probe. U937 cells responded to LPS (1μgml) ConA(50μg ml), PAF(100ng/ml) and Zymosan A(0.25mg ml) with an increase in [Ca2+]i, whereas macrophages responded only to Zymosan A(0.25mg/ml), Con A(50μg/ml), PAF(100ng /ml) but not to LPS. Experimental result showed that the increase of [Ca2+]i was due to both Ca2+ release from Intracellular stores and Ca2+ influx.Zymosan A worked as the most effective agent and could decrease the membrance fluidity of macrophages during respiratory burst. When there is Ca2+ in the buffer outside of cells, the respiratory burst can be stronger. It was also proved that after macrophages exposed to PAF (100ng/mnl), acid phosphatase increased in cytoplasm and cytokeleton was more stretched.Our present work shows unequivocally that Ca2+ dose play an important role in the early state of macrophage activation.