Comparison of advantages of two kinds of ovarian resection in establishing osteoporosis model in rats

Objective To compare the simplicity and safety of two operative methods in inducing osteoporosis in rats. Methods Forty 3-month old female SD rats were divided into two groups randomly:OVX 1 group (n=20) and OVX 2 group (n=20). In the first group, ovariectomy was a double dorsal-lateral incision. In the second group, ovariectomy was a midline abdominal incision. Surgical operation time, blood loss, postoperative complications and BMD were compared between two groups. Results The average operation time of OVX 1 group was significantly shorter than that of OVX 2 group (26.35±7.55 min vs 30.95±6.39 min, P< 0.05). The average blood loss of OVX 1 group and OVX 2 group was 1.81±0.81 g and 1.82±0.77 g, respectively, with no significant difference (P> 0.05). The level of surgery time and blood loss were negative correlated with the number of rats in OVX 1 and OVX 2 group (r=-0.846 8, P=0.000, r=-0.788 2, P=0.000; r=-0.903 4, P=0.000, r=-0.891 2, P=0.000). One case in OVX 2 group had complication of incision infection. No rats died in two groups. All rats had undergone Dual X-ray Absorptiometry (DXA) Measurement before and three months after operation. The bone mineral density (BMD) of the fifth lumbar was 0.376±0.021 g/cm²before operation and 0.264±0.026 g/cm²three months after operation in OVX 1 group, and 0.371±0.016 g/cm²and 0.275±0.019 g/cm²in OVX 2 group, which were significantly reduced (P< 0.05). Rats in OVX 2 group had severe abdominal cavity adhesion after three month. Conclusion The double dorsal-lateral incision of ovariectomization is technically easier, less time consuming and more safety in establishing the rat model of osteoporosis.