甲状旁腺素对成骨样细胞增殖的调节作用

The Proliferative Effect of Parathyroid Hormone on Rat Osteoblast like Cells

甲状旁腺素（ＰＴＨ）是调节钙磷代谢的经典激素，有报道ＰＴＨ对其靶细胞－成骨细胞有促增殖分化作用。经多层次、多水平的实验研究证实，ＰＴＨ对成骨样细胞ＲＯＳ１７／２．８确有促增殖作用。（１）细胞计数、ＭＴＴ［３－（４，５－ｄｉｍｅｔｈｙｌｔｈｉａ－ｚｏｌ－ｚ－ｙｉ）２，５－ｄｉｐｈｅｎｙｌｔｅｔｒａｚｏｌｉｕｍｂｒｏｍｉｄｅ］测定及ＳＲＢ（ｓｏｄｉｕｍｒｈｏｄａｍｉｎｅＢ，ＳＲＢ）染色均显示经ＰＴＨ（１０－９ｍｏｌ／Ｌ）处理的细胞，其数目明显增加；（２）３Ｈ－ＴｄＲ参入增加；（３）与增殖相关的原癌基因（ｃ－ｆｏｓ、ｃ－ｊｕｎ、ｃ－ｋｉ－ｒａｓ和ｃ－ｍｙｃ）的表达增强；（４）成骨细胞特征性蛋白－碱性磷酸酶活性降低．这些结果不仅表明该激素具有非经典样作用。

Parathyroid hormone(PTH) is regarded conventionally as a regulator of homeostasis of calcium and phosphate in extracellular fluid. It has been reported recently that intermittent pulses of PTH stimulate bone formation in animals and humans. It is suggested that the anabolic effect of PTH on bone is partly due to a stimulation of osteoblast proliferation. The objectives were to determine if PTH would induce the proliferative effect on rat osteoblast like ROS 17/2.8 cells. Cells were treated with PTH (10 9 mol/L) for 8 days,the result demonstrated that cell growth could be increased by PTH treatment, 3H TdR incorporation, MTT [3 (4,5 dimethylthia zol z yi)2,5 diphenyl tetrazolium bromide] assay and SRB (sodium rhodamine B) assay were all signi ficantly enhanced as well. PTH could also induce the gene expression of proto oncogenes,c fos,c jun,c myc and c ki ras.Furthermore,the activity of alkaline phosphatase, a differential maturation marker protein of bone cells, was depressed after PTH treatment. Thus,all these findings provide further support for the anabolic effect of PTH on osteoblast like cells. However, other growth factors and/or cytokines may have synergistic action with PTH on bone cell proliferation.