title: [Effect of different-intensity SEMFs on bone mineral density and histomorphometry in SD rats].
abstract: OBJECTIVE
  To investigate the effects of different-intensity sinusoidal electromagnetic fields (SEMFs) on bone mineral density (BMD) and histomorphometry in SD rats.
  
  
  METHODS
  Thirty female SD rats were randomly divided into three groups: group A (a control group), group B (0.1 mT group) and group C (0.6 mT group). The rats in group B and C were exposed to 50 Hz SEMFs 3 hours each day. However,the magnetic intensity was different between group B and group C:0.1 mT for group B and 0.6 mT for group C. After 8 weeks, all the animals were killed. Changes of BMD and histomorphometric properties were observed.
  
  
  RESULTS
  Compared with group A, the BMD of whole body, femur and vertebrae of rats in group B increased significantly; the area percentage, number and width of bone trabeculae in vertebrae and femur of rats in group B were larger than those of group A; but the resolution of bone trabeculae of rats in group B was lower than that of group A. The trabecular number in group C rats were significantly decreased, compared with that in group A rats. The outcome of double fluorescence labeling in group B was found to be significantly different with that in group A. But the difference between rats in group A and C was not significant.
  
  
  CONCLUSIONS
  This study demonstrates that 50 Hz 0.1 mT SEMFs can increase BMD, improve bone tissue microstructure and, promote bone formation.
authors.affiliation: Institute of Orthopaedics, Lanzhou General Hospital of PLA, Gansu, China.
authors.forename: Yu-hai
authors.initials: YH
authors.lastname: Gao
authors.forename: Kui
authors.initials: K
authors.lastname: Cheng
authors.forename: Bao-Feng
authors.initials: BF
authors.lastname: Ge
authors.forename: Ping
authors.initials: P
authors.lastname: Zhen
authors.forename: Jian
authors.initials: J
authors.lastname: Zhou
authors.forename: Xiao-Ni
authors.initials: XN
authors.lastname: Ma
authors.forename: Shao-Feng
authors.initials: SF
authors.lastname: Li
authors.forename: Ke-Ming
authors.initials: KM
authors.lastname: Chen
mesh_terms: D000818:Animals; D015519:Bone Density / Q000528:radiation effects*; D004574:Electromagnetic Fields; D005260:Female; D008159:Lumbar Vertebrae / Q000473:pathology / Q000528:radiation effects*; D010012:Osteogenesis / Q000528:radiation effects; D051381:Rats; D017207:Rats, Sprague-Dawley; D013977:Tibia / Q000473:pathology / Q000528:radiation effects*