甲状旁腺素对人成骨肉瘤细胞株SaOS-2内cAMP,IP3,Ca~(2+)的作用研究

目的通过研究ｈＰＴＨ（１～３４）对人成骨肉瘤细胞株ＳａＯＳ－２胞浆内ｃＡＭＰ、ＩＰ３、Ｃａ２＋的影响，来阐明ＰＴＨ与其膜上特异受体结合后的胞浆内主要信息传递途径。方法利用蛋白竞争结合法测定胞浆内ｃＡＭＰ，以Ｆｌｕｏ－３／ＡＭ作为荧光指示剂，激光共聚焦显微系统显示ＳａＯＳ－２内［Ｃａ２＋］ｉ的变化，离子交换层析法测定ｈＰＴＨ（１～３４）作用下胞浆内ＩＰ３的改变。结果ｈＰＴＨ（１～３４）可使ＳａＯＳ－２胞浆内ｃＡＭＰ明显升高且与其浓度呈正相关，其最佳作用时间为１０ｍｉｎ。ｈＰＴＨ（１～３４）能迅速提高ＳａＯＳ－２内［Ｃａ２＋］ｉ，而且作用３０ｓ时ＳａＯＳ－２胞浆内ＩＰ３升高即达最高峰，未发现百日咳毒素对此现象有抑制作用。结论ｃＡＭＰ及ＩＰ３／Ｃａ２＋两条信息途径均参与ｈＰＴＨ（１～３４）对成骨细胞的调节作用

Effect of parathyroid hormone(1-34) on cAMP,IP 3,Ca~(2 ) production in SaOS_2

AIM In order to classify the PTH stimulated signal transduction on osteoblast, we study the changes of 3′,5′ cyclic monophosphate(cAMP), 1,4,5 trisphosphate(IP 3) and Ca 2+ in the cytosolic of SaOS 2, a cell line with an osteoblastic phenotype. METHOD Protein competitive binding technique. RESULTS hPTH(1￣34) increase cytosolic cAMP in a dose related manner, and the best time is 10 minutes. hPTH(1￣34) could increase intracellular free calcium quickly using fluo 3/AM as fluorescent marker and confocal imaging system. The increase in 1,4,5 trisphosphates was quickly under the effect of PTH in 30 seconds by anion exchange chromatogrophy. Pretreatment SaOS 2 with pertussis toxin had no effect on PTH stimulation of inositol phosphates. CONCLUSLON These data suggest that cAMP and IP 3/Ca 2+ invole in the second messenge transmission of PTH in osteoblast cell.