title: Effects of electroacupuncture on bone mass and cathepsin K expression in ovariectomised rats.
abstract: OBJECTIVE
  To characterise the effects of early and late electroacupuncture (EA) treatment on serum 17β-oestradiol (E2), C-terminal cross-linking telopeptide of type I collagen (CTX-I), bone mineral density (BMD), biomechanical bone strength and mRNA expression of cathepsin K in ovariectomised (OVX) rats.
  
  
  METHODS
  Sixty Sprague-Dawley rats underwent ovariectomy (n=40) or sham surgery (n=20) and were randomly divided into two batches. Batch 1 (n=30) consisted of 10 sham-operated rats (Sham-0 group) and 20 OVX rats: half commenced EA immediately (early EA group, n=10) and half were left untreated (OVX-0 group, n=10). Batch 2 (n=30) consisted of 10 sham-operated rats (Sham-12 group) and 20 OVX rats: half commenced EA treatment 12 weeks after ovariectomy (late EA group, n=10) and half were left untreated (OVX-12 group, n=10). Rats in batches 1 and 2 were killed after 12 and 24 weeks, respectively. Serum E2, CTX-I, BMD, bone strength and cathepsin K expression were determined by ELISA, dual energy X-ray absorptiometry, biomechanical assessment and qRT-PCR, respectively.
  
  
  RESULTS
  Both early and late EA treatment increased serum E2 levels, reduced serum CTX- I levels and increased BMD and bone strength of the L5 vertebral body in OVX rats. Although early EA treatment similarly increased BMD and bone strength of the femur, late EA treatment did not. However, both early and late EA treatment reduced mRNA expression of cathepsin K in OVX rats.
  
  
  CONCLUSIONS
  Early EA completely prevented and late EA partially prevented bone loss and deterioration of bone strength in OVX rats. The timing of initiation of EA treatment may be an important consideration for optimisation of effects. The influence of EA on bone strength appears to be at least partially mediated through regulation of the expression of cathepsin K.
authors.affiliation: Department of Rehabilitation, The First Affiliated Hospital of University of South China, Hengyang, Hunan, People's Republic of China.
authors.forename: Jun
authors.initials: J
authors.lastname: Zhou
authors.affiliation: Hunan Polytechnic of Environment and Biology, Hengyang, Hunan, People's Republic of China.
authors.forename: Xinhong
authors.initials: X
authors.lastname: Li
authors.affiliation: Department of Rehabilitation, The First Affiliated Hospital of University of South China, Hengyang, Hunan, People's Republic of China.
authors.forename: Ying
authors.initials: Y
authors.lastname: Liao
authors.affiliation: Department of Rehabilitation, The First Affiliated Hospital of University of South China, Hengyang, Hunan, People's Republic of China.
authors.forename: Weibing
authors.initials: W
authors.lastname: Feng
authors.affiliation: Department of Rehabilitation, The First Affiliated Hospital of University of South China, Hengyang, Hunan, People's Republic of China.
authors.forename: Xin
authors.initials: X
authors.lastname: Guo
mesh_terms: D000818:Animals; D015519:Bone Density; D001842:Bone and Bones / Q000378:metabolism*; D056657:Cathepsin K / Q000235:genetics / Q000378:metabolism*; D024042:Collagen Type I / Q000097:blood; D015671:Electroacupuncture; D004958:Estradiol / Q000097:blood; D005260:Female; D005269:Femur / Q000378:metabolism; D008159:Lumbar Vertebrae / Q000378:metabolism; D010024:Osteoporosis / Q000097:blood / Q000378:metabolism / Q000517:prevention & control*; D010052:Ovariectomy; D010455:Peptides / Q000097:blood; D012333:RNA, Messenger / Q000378:metabolism; D017207:Rats, Sprague-Dawley
chemical_list: D024042:Collagen Type I; D010455:Peptides; D012333:RNA, Messenger; C052929:collagen type I trimeric cross-linked peptide; D004958:Estradiol; D056657:Cathepsin K