锌对大鼠成骨细胞膜Ca^(2+)-ATP酶活性的调节

Zinc modulates the Ca ^(2+ ) ATPase activity of rat osteoblast membrane

为了研究锌对大鼠成骨细胞膜Ca2+ -ATP酶和Na+ 、K+ -ATP酶活性的影响及其机制,实验设对照组和3个补锌组。采用孔雀绿比色法同步测定膜Ca2+ -ATP酶和Na+ ,K+ -ATP酶活性,以研究Zn2+ 对酶活性的影响以及蛋白激酶C或钙调素特异性抑制剂对Zn2+ 诱导的成骨细胞膜Ca2+ -ATP酶活性的影响。结果表明,Zn2+ 可以显著提高成骨细胞膜Ca2+ -ATP酶活性,但对Na+ ,K+ -ATPase活性无影响;钙调素特异性抑制剂R24571对Zn2+ 诱导的Ca2+ -ATPase活性无影响,钙调素对膜Ca2+ -ATP酶基础活性也无激活作用;蛋白激酶C特异性抑制剂三氟拉嗪可使Zn2+ 诱导的Ca2+ -ATP酶的活性显著降低。因此,锌可能通过蛋白激酶C介导调节成骨细胞膜Ca2+

The effect and mechanism of zinc on Ca 2+ ATPase and Na +,K + ATPase activity of rat osteoblast membrane were studied.The activities were measured by colorimetric method.The effect of special inhibitors of protein kinase C or calmodulin on membrane Ca 2+ ATPase and Na +,K + ATPase activity which induced by zinc were also examined.The results showed that zinc could increase membrane Ca 2+ ATPase activity,but no influence was observed on Na +,K + ATPase activity.R24571,a special inhibitor of calmodulin,had no effect on membrane Ca 2+ ATPase activity. Calmodulin also could not promote the basic Ca 2+ ATPase activity of membrane.But trifluoperazine,a special inhibitor of protein kinase C,obviously reduced its activity.It was concluded that the modulation of zinc on membrane Ca 2+ ATPase activity of rat osteoblast could be mediated by protein kinase C.