Effects of C-terminal fragment of parathyroid hormone-related protein on bone metabolism in ovariectomized rats / 中华风湿病学杂志

ABSTRACT

Objective To investigate the effects of C-terminal fragment of parathyroid hormonerelated protein (PTHrP107-139) on bone mineral density (BMD), bone histomorphometry and biomechanical properties in ovariectomized (OVX) rats and its effect on bone metabolism is also explored. Methods Forty 4-month old female Wistar rats in which 30 were ovariectomized and then divided into 3 groups: the placebo, the PTHrPC and the CT groups, the other 10 rats were Sham-operated as the control group (Sham). Five weeks later, the rats of PTHrPC and CT groups were subcutaneously injected with PTHrP107-139 (40 μg/kg) and Salmon Calcitonin (15 U/kg) respectively once every other day. The rats of the placebo and sham groups were injected with 0.2 ml saline once every other day. After treatment of 12 weeks, all rats were sacrificed and all samples were collected and analyzed. Results ① Compared with the placebo, the BMD and bone strength of PTHrPC and CT groups were significantly increased (P<0.05). ② Histomorphometry revealed that the tetracycline labeled bone surfaces, osteoid surfaces, mineral apposition rate and bone resorption rate were remarkably decreased in PTHrPC, and CT groups comparing with those of the placebo group. Conclusion Cter-minal PTHrP107-139 is effective in increasing the BMD, bone strength and quality when administered intermittently to ovariectomy-induced osteoporotic rats. Its increasing in bone quality may relate to reducing bone turnover and inhibiting resorption.