title: Effect of combined sex hormone replacement on bone/cartilage turnover in a murine model of osteoarthritis.
abstract: BACKGROUND
  Estrogens act on estrogen receptors distributed in articular cartilages, synovial membrane, and ligaments, which are thought to be related with degenerative changes. Meanwhile, progesterone is known to have a weak anabolic action on bone formation This study evaluates the effects of estrogen and progesterone hormone on bone/cartilage turnover in ovariectomized (OVX) rats.
  
  
  METHODS
  Thirty-five 7-month-old female Sprague-Dawley rats were randomly divided into 5 groups and then ovariectomized bilaterally except the sham control group. The first and the second group acting as controls did not receive hormonal therapy, the third group received estrogen, the fourth group received progesterone, and the fifth group received combination of both hormones 10 weeks after surgery. Evaluations were done using the serum levels of cartilage oligomeric matrix protein (COMP) for cartilage turnover, collagen type I C-telopeptide (CTX-1) and osteocalcin (OC) for bone turnover at 11, 15, 19 weeks after OVX and histology using the Osteoarthritis Research Society International (OARSI) osteoarthritis (OA) cartilage histopathology assessment system.
  
  
  RESULTS
  Significantly less cartilage degradation (decreased levels of COMP) was found in the combined hormone treated group in comparison with OVX group. Similarly, both hormonal treatment resulted in increased bone formation and decreased bone resorption i.e., a low overall bone turnover status (decrease in the serum OC and CTX-1 levels).
  
  
  CONCLUSIONS
  Combined estrogen and progesterone therapy was found to be convincing in terms of reducing the severity of OA in this experimental model.
authors.affiliation: Department of Orthopaedic Surgery, Seoul Veterans Hospital, Seoul, Korea.
authors.forename: Jae-Hyuk
authors.initials: JH
authors.lastname: Yang
authors.forename: Ji-Hun
authors.initials: JH
authors.lastname: Kim
authors.forename: Deuk-Soo
authors.initials: DS
authors.lastname: Lim
authors.forename: Kwang-Jun
authors.initials: KJ
authors.lastname: Oh
mesh_terms: D000818:Animals; D015415:Biomarkers / Q000097:blood / Q000378:metabolism; D016723:Bone Remodeling / Q000187:drug effects*; D001842:Bone and Bones / Q000737:chemistry / Q000187:drug effects; D002356:Cartilage / Q000737:chemistry / Q000187:drug effects*; D024042:Collagen Type I / Q000097:blood / Q000378:metabolism; D004195:Disease Models, Animal; D004967:Estrogens / Q000494:pharmacology*; D016326:Extracellular Matrix Proteins / Q000097:blood / Q000378:metabolism; D005260:Female; D006023:Glycoproteins / Q000097:blood / Q000378:metabolism; D006651:Histocytochemistry; D020249:Hormone Replacement Therapy / Q000379:methods*; D064235:Matrilin Proteins; D010003:Osteoarthritis / Q000097:blood / Q000188:drug therapy*; D015675:Osteocalcin / Q000097:blood / Q000378:metabolism; D010052:Ovariectomy; D011374:Progesterone / Q000494:pharmacology*; D051381:Rats; D017207:Rats, Sprague-Dawley
chemical_list: D015415:Biomarkers; D024042:Collagen Type I; D004967:Estrogens; D016326:Extracellular Matrix Proteins; D006023:Glycoproteins; D064235:Matrilin Proteins; D015675:Osteocalcin; D011374:Progesterone