17β-雌二醇对人的类成骨细胞HOS TE85胞内游离钙、IP_3及钙调蛋白影响

Effects of 17β estradiol on Intracellular Free Calcium, Inositol 1,4,5 trisphophate and Calmodulin in Human Osteoblast like Osteosarcoma Cell Line TE85

目的观察１７β－雌二醇（Ｅ２）对成骨细胞胞内游离钙（［Ｃａ２＋］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［Ｃａ２＋］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。结果给予０．１、１．０ｎｍｏｌ／ＬＥ２后５０ｓ胞内钙荧光值分别增加４．７和６．１倍，持续８０～１６０ｓ；以１００ｎｍｏｌ／Ｌｔｈａｐｓｉｇａｒｇｉｎ预处理细胞，Ｅ２仅使胞内钙荧光值升高１．５倍。加入１．０ｎｍｏｌ／ＬＥ２，ＩＰ３含量在给药后２０～３０ｓ和６０～７０ｓ呈双峰升高。同样剂量的Ｅ２可使ＣａＭ含量增加８５．２％。他莫西芬不能阻断Ｅ２引起的胞内钙荧光值、ＩＰ３及ＣａＭ含量升高的作用，而磷脂酶Ｃ抑制剂使Ｅ２的作用部分或完全抑制。结论Ｅ２作用于胞膜引起胞外钙内流，并通过ＩＰ３导致［Ｃａ２＋］ｉ进一步增加，激活ＣａＭ从而调节细胞功能。

Objective To study the effects of 17β estradiol (E 2) on intracellular free calcium ([Ca 2+ ] i), inositol 1,4,5 trisphophate (IP 3) and calmodulin (CaM) in human osteoblast like cell line TE85. Methods Using Fluo 3/AM as fluorescent indicator, the [Ca 2+ ] i was measured by laser confocal microscopy system. The IP 3 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 E 2 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 E 2 caused only 1.5 times elevation in fluorescence. E 2 induced a concommitant bi peak increase in IP 3 content. At the presence of E 2 (1.0 nmol/L), the CaM content increased by 85.2%. Tamoxifen did not affect the effect of E 2 on [Ca 2+ ] i, IP 3 and CaM content. But, the inhibitor of phospholipase C (neomycin) and pertusis toxin depressed them partly or completely. Conclusions E 2 regulate bone cells function by way of Ca 2+ /CaM activation.