title: The influence of long-term treadmill exercise on bone mass and articular cartilage in ovariectomized rats.
abstract: BACKGROUND
  Loss of bone quality and deterioration of articular cartilage are commonly seen after menopause. While exercise may protect against tissue degeneration, a clear link has yet to be established. The aim of the present study is to investigate the influence of long-term treadmill exercise on changes in bone mass and articular cartilage in ovariectomized rats.
  
  
  METHODS
  Sixty female Sprague-Dawley rats were randomly assigned to 4 groups: ovariectomized (OVX), ovariectomized plus treadmill exercise (OVX-RUN), treadmill exercise alone (RUN), and control (CON) groups. After 36 weeks, the following variables were compared among the 4 groups. Bone mass was evaluated by trabecular bone volume and bone mineral density (BMD). Articular cartilage in the knee joints was evaluated by histology analysis and a modified Mankin score.
  
  
  RESULTS
  Rats in the ovariectomized groups (OVX and OVX-RUN) had significantly lower BMD and bone mass than the non-ovariectomized rats (CON and RUN), indicating that exercise did little to preserve bone mass. However, the sedentary OVX group had a significantly worse modified Mankin score (7.7 +/- 1.4) than the OVX-RUN group (4.8 +/- 1.0), whose scores did not differ significantly from the other 2 non-operated groups. The articular cartilage in the sedentary OVX rats was relatively thinner, hypocellular, and had more clefts than in the other 3 groups.
  
  
  CONCLUSIONS
  This study suggests that long-term exercise protects articular cartilage in OVX rats but does not retard the loss of bone mass seen in after menopause.
authors: Institute of Biomedical Engineering, National Yang Ming University, Taipei, Taiwan.
authors: Ting-Kuo
authors: TK
authors: Chang
authors: Chang-Hung
authors: CH
authors: Huang
authors: Chun-Hsiung
authors: CH
authors: Huang
authors: Hsuan-Chiang
authors: HC
authors: Chen
authors: Cheng-Kung
authors: CK
authors: Cheng
mesh_terms: D000818:Animals; D015519:Bone Density / Q000502:physiology*; D002358:Cartilage, Articular / Q000166:cytology / Q000502:physiology*; D004195:Disease Models, Animal; D005080:Exercise Test / Q000379:methods*; D005081:Exercise Therapy / Q000009:adverse effects / Q000295:instrumentation* / Q000379:methods*; D005260:Female; D006801:Humans; D007719:Knee Joint / Q000166:cytology / Q000502:physiology; D020370:Osteoarthritis, Knee / Q000473:pathology / Q000503:physiopathology / Q000628:therapy; D015663:Osteoporosis, Postmenopausal / Q000473:pathology / Q000503:physiopathology / Q000628:therapy; D010052:Ovariectomy / Q000009:adverse effects; D051381:Rats; D017207:Rats, Sprague-Dawley; D013997:Time Factors; D016896:Treatment Outcome