Effects of recombinant human parathyroid hormone_(1-34) (rhPTH_(1-34)) on osteoblast proliferation and collagen I and Osterix mRNA expression

Objective To observe the effect of rhPTH1-34 on osteoblast proliferation and the mRNA expression of collagen I and Osterix in vitro,and to explore the mechanism of the effect of rhPTH1-34 on osteoblast in vitro.Methods Cultured osteoblasts of the new-born rat were intervened with 0,10-11,10-10,10-9,10-8,and 10-7 M rhPTH1-34,2 times at the first 12 h in a 24-hour cycle.Cell proliferation was assessed with MTT colorimetric assay.The expression of collagen Ⅰ and Osterix mRNA were examined with semi-quantitive RT-PCR.Results rhPTH1-34 sifnificantly induced osteoblast proliferation(P 0.05),and stimulated the expression of collagen Ⅰ and Osterix(P 0.05).It was most remarkable at 10-9 M concentration with a does-dependent manner.Conclusion rhPTH1-34 promotes the proliferation,differentiation of the osteoblast,probably by increasing the expression of collagen Ⅰ and Osterix mRNA.