1,25-(OH)_2D_3诱导HL-60细胞分化后胞液Ca~(2+)浓度、磷酸化酶a和微粒体Ca~(2+)-ATP酶活性的改变

1,25-(OH)_2D_3对HL-60细胞具有促分化作用。本文报道了1,25-(OH)_2D_3在促进HL-60细胞分化前后胞液Ca~(2+)浓度、磷酸化酶a和微粒体Ca~(2+)-ATP酶活性的改变。结果表明,1,25-(OH)_2D_3加入HL-60细胞培养液后72小时,细胞NBT染色阳性率高于70％,形态向正常分化的细胞转化。同对,胞液Ca~(2+)浓度和微粒体Ca~(2+)-ATP酶活性明显降低,而磷酸化酶a活性显著升高。结果提示,在1,25-(OH)2_D_3作用下,HL-60细胞不仅杀菌功能增强,细胞内胞液Ca~(2+)浓度趋向正常,与钙恒稳有关的酶活性也同样发生改变。即1,25-(OH)_2D_3对HL-60细胞的诱导作用伴有钙恒稳的改变。这些变化与DMSO的作用相同。

Changes of Cytosolic Ca~(2+) Concentration, Phosphorylase a,and Microsomal Ca~(2+)-ATPase Activity of HL-60 Cells After 1,25- (OH) _2D~3-induced differentiation

1,25-(OH)2D3 was reported to show the effects of inducing differentiation of HL-60 cells. In this work, the changes in concentration of cytosolic Ca2+,activity of cytosolic phosphorylase a and microsomal Ca2+-ATPase were determined, and the following results were obtained. After 72 h culture of HL-60 cells in the presence of 1,25-(OH)2D3, more than 70% of HL-60 cells showed positive reaction to NBT test indicating that differentiation of HL-60 cell was induced, The concentr- ation of cytosolic Ca2+ and the activity of microsomal Ca2+-ATPase was decreased obviously while the activity of phosphorylase a was increased remarkably.These results indicated that under the inducing effect of 1,25-(OH) 2D3 the bactericidal effect of HL-60 cells was strenthened, the concentration of cytosolic Ca 2+ tended to normal level and the activity of enzymes concerning with Ca2+ homeostasis were changed simultaneously. In other words, the inducing effect of 1,25-(OH)2D3 on HL-60 cells was accompanied by the changes of Ca2+ homeostasis. The same results were also found in cells under the inducing effect of DMSO.