title: Effect of dynamic compression on in vitro chondrocyte metabolism.
abstract: BACKGROUND
  Chondrocytes can detect and respond to the mechanical environment by altering their metabolism. This study was designed to explore the effects of dynamic compression on chondrocyte metabolism.
  
  
  METHODS
  Chondrocytes were harvested from newborn Wistar rats. After 7 days of expansion, chondrocytes embedded in agarose discs underwent uniaxial unconfined dynamic compression loads at different amplitudes (5%, 10%, and 15%) and frequencies (0.5 Hz, 1.0 Hz, 2.0 Hz, and 3.0 Hz) with a duration of 24 hours. The delayed effects on the chondrocytes were studied at 1, 3, and 7 days after the experiment.
  
  
  RESULTS
  The results showed that at 10% strain, higher-frequency compression pressure can enhance the proliferation of chondrocytes. The synthesis of glycosaminoglycan (GAG) increased at 10%-15% strain and a 1-Hz load. The synthesis of nitric oxide (NO) increased at the 0.5-Hz load; while decreasing at the 15% strain. With 10% strain, 1 Hz dynamic compression, the proliferation of chondrocytes and GAG synthesis increased and persisted for 7 days, and NO synthesis decreased at the third and seventh days of culture.
  
  
  CONCLUSIONS
  This study showed that chondrocytes respond metabolically to compressive loading, which is expected to modulate the growth and the resultant biomechanical properties of these tissue-engineered constructs during culture.
authors.affiliation: Department of Orthopedic Surgery, Taipei City Hospital, Taipei, Taiwan - ROC.
authors.forename: Y-H
authors.initials: YH
authors.lastname: Tsuang
authors.forename: Y-S
authors.initials: YS
authors.lastname: Lin
authors.forename: L-T
authors.initials: LT
authors.lastname: Chen
authors.forename: C-K
authors.initials: CK
authors.lastname: Cheng
authors.forename: J-S
authors.initials: JS
authors.lastname: Sun
mesh_terms: D000818:Animals; D002478:Cells, Cultured; D019902:Chondrocytes / Q000378:metabolism*; D006025:Glycosaminoglycans / Q000096:biosynthesis; D009569:Nitric Oxide / Q000378:metabolism; D051381:Rats; D013314:Stress, Mechanical; D014732:Vibration / Q000009:adverse effects
chemical_list: D006025:Glycosaminoglycans; D009569:Nitric Oxide