17β—雌二醇对人的类成骨细胞HOS TE85胞内游离钙,IP3及？…

目的 观察１７β－雌二醇（Ｅ２０）对成骨细胞内游离钙（「Ｃａ＾２＋」ｉ）１,４,５,－三磷酸肌醇（ＩＰ３）含量及钙调蛋白（ＣａＭ）含量的影响。方法 以Ｆｌｕｏ－３／ＡＭ为钙荧光指示剂,采用激光共聚焦显微系统测定细胞内钙荧光值的改变,以反映「Ｃａ＾２＋」ｉ含量的变化。用阳离子交换法测定ＩＰ３含量。以测定钙依赖的磷酸二酯酶活性方法测定ＣａＭ含量。

Effects of 17 beta-estradiol on intracellular free calcium,inositol-1,4,5-trisphophate and calmodulin in human osteoblast-like osteosarcoma cell line TE85

OBJECTIVE: To study the effects of 17 beta-estradiol (E2) on intracellular free calcium (Ca2+]i), inositol-1,4,5-trisphophate (IP3) and calmodulin (CaM) in human osteoblast-like cell line TE85. METHODS: Using Fluo-3/AM as fluorescent indicator, the Ca2+]i was measured by laser confocal microscopy system. The IP3 content was determined by anion-exchange chromatography. CaM content was detected by a high sensitive assay based on stimulation of Ca(2+)-dependent phosphodiesterase activity. RESULTS: E2 at dose of 0.1 and 1.0 nmol/L increased fluorescent level by 4.7 and 6.1 times. Pretreatment with thapsigargin (100 nmol/L), the E2 caused only 1.5 times elevation in fluorescence. E2 induced a concommitant bi-peak increase in IP3 content. At the presence of E2(1.0 nmol/L), the CaM content increased by 85.2%. Tamoxifen did not affect the effect of E2 on Ca2+]i, IP3 and CaM content. But, the inhibitor of phospholipase C (neomycin) and pertusis toxin depressed them partly or completely. CONCLUSIONS: E2 regulate bone cells function by way of Ca2+/CaM activation.