ABSTRACT
Objective To observe serum and callus leptin expression in rats model with fracture and traumatic spinal cord injury (SCI). Methods 72 male SD rats were randomized equally into 4 groups: control, SCI group, fracture group, and fracture/SCI group. Rats were sacrificed at 7, 14, 21 and 28 days after fracture/SCI. Serum leptin was detected by radioimmunoassayat 1, 7, 14, 21 and 28 days, and callus formation was measured radiologically at 14, 21 and 28 days. Callus leptin was analyzed with immunohistochemistry. Results Serum leptin in the fracture group, SCI group and combined fracture/SCI group were all higher than in control group at the 1, 7, 14 and 21 day time-point (P < 0.05). Serum leptin in the combined fracture/SCI group was significantly higher than the fracture group at 7, 14 and 21 days (P < 0.05), and higher than SCI groups at 14 and 21 days after operation (P < 0.05). The percentage of leptin-positive cells in the fracture/SCI callus, and callus volume was significantly higher than the fracture-only group (P < 0.001). Conclusions Leptin expression increases in the recovery process after SCI, and the recovery of fracture becomes sooner.