Document Detail

Proteoglycan metabolism and viability of articular cartilage explants as modulated by the frequency of intermittent loading.
MedLine Citation:
PMID:  12744940     Owner:  NLM     Status:  MEDLINE    
OBJECTIVE: This study was designed to systematically determine whether and to what extent the frequency of intermittent loading modulates the biosynthesis and release of proteoglycans (PGs), and to assess chondrocyte viability within mature bovine articular cartilage explants exposed to different loading patterns. METHODS: Cultured full-thickness cartilage explants from the weight-bearing area of healthy bovine fetlock joints were exposed to intermittently applied, uniaxial cyclic loads by introducing a sinusoidal waveform of 0.1, 0.5 or 1.0Hz, frequency and a peak stress of 0.5MPa for a period of 6 days. The cyclic loads were applied for 5, 10 or 20s followed by a period of unloading lasting 10, 100 or 1000s. The incorporation of radiolabeled sulfate into glycosaminoglycans (GAGs) during the final 18h, the content of GAGs and DNA, the deformation of loaded explants as well as the viability of chondrocytes within the different zones of explants were determined. RESULTS: PG synthesis and loss of endogenous PGs were non-linearly and independently regulated by the frequency of the chosen intermittent load, whereas the release of newly synthesized PGs remained unaffected. The viability of chondrocytes within the superficial zone decreased drastically under intermittent loading in a manner independent of the frequency applied. CONCLUSIONS: Our results confirm the hypothesis that the frequency of intermittent loading is an important mechanical factor controlling the metabolic activities of chondrocytes. They also implicate that an initially healthy cartilage explant can be mechanically manipulated to generate an in vitro model of degenerative, osteoarthritic-like cartilage.
K Sauerland; R X Raiss; J Steinmeyer
Publication Detail:
Type:  Journal Article; Research Support, Non-U.S. Gov't    
Journal Detail:
Title:  Osteoarthritis and cartilage / OARS, Osteoarthritis Research Society     Volume:  11     ISSN:  1063-4584     ISO Abbreviation:  Osteoarthr. Cartil.     Publication Date:  2003 May 
Date Detail:
Created Date:  2003-05-14     Completed Date:  2003-07-21     Revised Date:  2006-11-15    
Medline Journal Info:
Nlm Unique ID:  9305697     Medline TA:  Osteoarthritis Cartilage     Country:  England    
Other Details:
Languages:  eng     Pagination:  343-50     Citation Subset:  IM; S    
Department of Pharmacology and Toxicology, Rheinische Friedrich-Wilhelms-Universität Bonn, Reuterstrasse 2b, D-53113 Bonn, Germany.
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MeSH Terms
Cartilage, Articular / metabolism*
Cells, Cultured
Chondrocytes / metabolism*
DNA / analysis
Models, Biological
Osteoarthritis / metabolism
Proteoglycans / biosynthesis,  metabolism*
Stress, Mechanical
Time Factors
Reg. No./Substance:
0/Proteoglycans; 9007-49-2/DNA

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine

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