The expression of insulin-like growth factor-Ⅰ mRNA and polypeptide in rat osteoblasts w

The expression of insulin-like growth factor-Ⅰ mRNA and polypeptide in rat osteoblasts with

exposure to parathyroid hormone

张克勤;陈家伟;王美莲;汪承亚;李光富;郑肇熙;赵人铮

【期刊名称】《中华医学杂志（英文版）》 【年(卷),期】2003(116)012

【摘要】Objective To investigate the insulin-like growth factor-Ⅰ (IGF-Ⅰ) gene and polypeptide expression in cultured rat osteoblast (ROB) and the role of IGF-Ⅰ in mediating the cell-to-cell communication by mimicking

the

pharmacokinetics

of

parathyroid

hormone

(PTH).Methods The ROB was cultured with three kinds of treatment: (1) Control (Ctr), the cells were cultured without PTH during the first 6 hours and the subsequent 42 hours in a 48-hour cycle; (2) Intermittent exposure to PTH (Itm), the cells were cultured with PTH during the first 6 hours, but without PTH in the subsequent 42 hours; and (3) Continuous exposure to PTH (Ctu), the cells were cultured with PTH during the first 6 hours and the subsequent 42 hours.Results The bone-forming activities of ROB were increased in Itm and inhibited in Ctu. The IGF-Ⅰ mRNA content in Itm cells was elevated only during the first 6 hours and that in Ctu cells was elevated at any time during an incubation cycle. The free IGF-Ⅰ concentration in the medium of Itm cells was generally higher and that of the Ctu cells was generally lower