Effect of recombinant human parathyroid hormone on bone fracture healing in the rat observed by micro-CT / 中国实验动物学报

ABSTRACT

Objective To investigate the accelerating role of recombinant human parathyroid hormone (PTH) in bone fracture repair.Methods 2-month old male Sprague-Dawley rats underwent closed unilateral femoral fracture and intramedullary nail fixation.The rats were divided into 2 equal groups randomly the treatment group receiving subcutaneous injection of rhPTH(1-34) 10 μg/(kg·d) immediately after operation and for 2,7,14,21 and 42 d,respectively, and the control group receiving subcutaneous injection of normal saline in the same volume.X-ray and micro-CT were conducted at 2, 7, 14, 21 and 42 days after surgery.Results The continuity of porosis between fracture sides was better and fracture line has been blurred in the PTH-treated group at 21 days after fracture compared with the control group, the bone volume (BV),BV/TV, bone mineral density(BMD)and trabecular pattern factor (Tb.Pf) were significantly higher, and trabecular separation (Tb.Sp) and degree of anisotropy (DA) were significantly lower in the PTH-treated group at 42 days after fracture.Conclusions Our findings suggest that a low dose recombinant human parathyroid hormone can accelerate the bone fracture healing, probably through improving the BV, BV/TV, Tb.P and BMD, and decreasing the Tb.Sp and DA.