Pulsed electromagnetic fields protect the balance between adipogenesis and osteogenesis on steroid-induced osteonecrosis of femoral head at the pre-collapse stage in rats

• Published in: Bioelectromagnetics 2014-04, Vol.35 (3), p.170-180
• Main Authors: Li, Jian-Ping, Chen, Sen, Peng, Hao, Zhou, Jian-Lin, Fang, Hong-Song
• Format: Article
• Language: English
• Subjects: Adipogenesis; Animals; Core Binding Factor Alpha 1 Subunit - metabolism; Electromagnetic Fields; Femur Head - pathology; Femur Head Necrosis - chemically induced; Femur Head Necrosis - pathology; Femur Head Necrosis - physiopathology; Femur Head Necrosis - therapy; glucocorticoids; ischemia necrosis of femoral head; Kidney - pathology; Lipopolysaccharides; Liver - pathology; Magnetic Field Therapy - instrumentation; Magnetic Field Therapy - methods; Male; Methylprednisolone - analogs & derivatives; Osteocytes - pathology; Osteocytes - physiology; Osteogenesis; peroxisome proliferator-activated receptor-γ2 (PPAR-γ2); PPAR gamma - metabolism; pulsed electromagnetic fields simulation; Rats; Rats, Wistar; RNA, Messenger - metabolism; Runt-related transcription factor 2 (Runx2)
• ISSN: 0197-8462; 1521-186X
• DOI: 10.1002/bem.21833

This study was designed to investigate the effects of pulsed electromagnetic fields (PEMF) on the balance of adipogenesis and osteogenesis on steroid‐induced osteonecrosis of the femoral head (OFH) in rats. Forty‐two rats were divided into three groups: Steroid group (S, n = 16); Steroid + PEMF group (S + P, n = 16); and Control group (C, n = 10). For groups S and S + P, all rats were first intravenously given 10 µg/kg lipopolysaccharide on day 1, and then intramuscularly injected with 20 mg/kg methylprednisolone acetate on days 2, 3, and 4, with an interval of 24 h. After 4 weeks, the S + P group was treated with PEMF (4.5‐ms square pulse, repeated at 15 Hz, with a peak of 1.2 mT) for 4 h a day for the next 8 weeks. Group S was not exposed to PEMF. Group C was chosen as the control group, without steroid use and exposure to PEMF. After 8 weeks of treatment, the histological changes, and mRNA and protein expressions of PPAR‐γ2 and Runx2 were measured and analyzed. Compared with the S group, lower incidence of osteonecrosis (31% vs. 69%, P