Steroid-associated osteonecrosis animal model in rats

Zheng, Li-Zhen; Wang, Jia-Li; Kong, Ling; Huang, Le; Tian, Li; Pang, Qian-Qian; Wang, Xin-Luan; Qin, Ling

Animals were divided and allocated to normal control group (n Z 12) and SAON group (n Z 16). The SAON induction procedures for the SAON group are shown in Fig. 1 . At day 1, under anaesthesia [90 mg/kg (ketamine) and 10 mg/kg (xylazine) intraperitoneally], each rat was intravenously injected with lipopolysaccharide (LPS, 0.2 mg/kg, Escherichia coli O111:B4; SigmaeAldrich, St. Louis, MO, USA) via tail vein steadily and slowly. The LPS injection time was controlled for 30 minutes. At day 2, 3 and 4, three intraperitoneal injections of high-dose methylprednisolone (MPS, 100 mg/kg body weight, Pfizer Manufacturing Belgium NV, Puurs, Belgium) were given, and then, low-dose MPS (40 mg/kg, i.p.) were given three times a week at week 2e6. The rats were euthanised by intravenous injection of overdose of pentobarbital at the end of week 2 and week 6. Bilateral femora and tibiae, liver and blood of each rat were collected for further analysis (Fig. 1 ).