TY - JOUR
T1 - Intermittent sub-ambient interstitial hydrostatic pressure as a potential mechanical stimulator for chondrocyte metabolism
AU - Suh, Jun Kyo
AU - Baek, Goo H.
AU - Arøen, Asbjørn
AU - Malin, Christina M.
AU - Niyibizi, Christopher
AU - Evans, Christopher H.
AU - Westerhausen-Larson, Andrea
N1 - Funding Information:
The study was supported by Whitaker Foundation, Ferguson Orthopaedic Research Foundation, the Competitive Medical Research Fund of the University of Pittsburgh Medical Center and the Dept. of Orthopaedic Surgery of the University of Pittsburgh. The authors would like to acknowledge technical supports of several people; Dr Peter K. Conrad for the measurement of partial oxygen pressure, Ms Charlene F. Rizzo for the northern analysis, and Mr Lance M. Brunton for other biochemical assays. Helpful suggestions from Drs Savio L-Y. Woo and Freddie H. Fu are also gratefully acknowledged.
PY - 1999/1
Y1 - 1999/1
N2 - Objective: Experimental findings have suggested that the metabolic activities of articular cartilage can be influenced by mechanical stimuli. Our mathematical analysis predicted that cyclic compressive loading may create periods of intermittent sub-ambient hydrostatic pressure within the cartilage extracellular matrix. Based on this mathematical analysis, the present study was aimed to investigate whether the intermittent sub-ambient hydrostatic pressure, created in the cartilage extracellular matrix during cyclic compression, has a stimulative effect on the biosynthesis of chondrocytes. Method: In order to test this hypothesiS, the present study developed a custom-designed sub-ambient pressure generator to subject a monolayer culture of chondrocytes to an intermittent sub-ambient pressure. Using this pressure generator, the monolayer chondrocyte culture system was analyzed for 35S-sulfate and 3H-proline incorporation rates for biosynthesis of proteoglycan and collagenous/noncollagenous protein molecules, respectively. Northern analyses for aggrecan and type II collagen mRNAs were also performed. Results: It was found that the intermittent sub- ambient pressure produced a 40% increase in proteoglycan and a 17% increase in non-collagenous protein synthesis during the pressurization period (P<0.05). The collagenous protein synthesis was not affected by the intermittent sub-ambient pressure regimen used in this study. After the intermittent sub-ambient pressurization, the metabolic activities of the chondrocytes returned to normal (control level). The intermittent sub- ambient pressure also produced an increase in the mRNA signals for aggrecan. Therefore, we conclude that intermittent sub-ambient pressure may be one of the potential mechanical stimulators of chondrocytes in articular cartilage during dynamic compression.
AB - Objective: Experimental findings have suggested that the metabolic activities of articular cartilage can be influenced by mechanical stimuli. Our mathematical analysis predicted that cyclic compressive loading may create periods of intermittent sub-ambient hydrostatic pressure within the cartilage extracellular matrix. Based on this mathematical analysis, the present study was aimed to investigate whether the intermittent sub-ambient hydrostatic pressure, created in the cartilage extracellular matrix during cyclic compression, has a stimulative effect on the biosynthesis of chondrocytes. Method: In order to test this hypothesiS, the present study developed a custom-designed sub-ambient pressure generator to subject a monolayer culture of chondrocytes to an intermittent sub-ambient pressure. Using this pressure generator, the monolayer chondrocyte culture system was analyzed for 35S-sulfate and 3H-proline incorporation rates for biosynthesis of proteoglycan and collagenous/noncollagenous protein molecules, respectively. Northern analyses for aggrecan and type II collagen mRNAs were also performed. Results: It was found that the intermittent sub- ambient pressure produced a 40% increase in proteoglycan and a 17% increase in non-collagenous protein synthesis during the pressurization period (P<0.05). The collagenous protein synthesis was not affected by the intermittent sub-ambient pressure regimen used in this study. After the intermittent sub-ambient pressurization, the metabolic activities of the chondrocytes returned to normal (control level). The intermittent sub- ambient pressure also produced an increase in the mRNA signals for aggrecan. Therefore, we conclude that intermittent sub-ambient pressure may be one of the potential mechanical stimulators of chondrocytes in articular cartilage during dynamic compression.
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U2 - 10.1053/joca.1998.0163
DO - 10.1053/joca.1998.0163
M3 - Article
C2 - 10367016
AN - SCOPUS:0032996199
SN - 1063-4584
VL - 7
SP - 71
EP - 80
JO - Osteoarthritis and Cartilage
JF - Osteoarthritis and Cartilage
IS - 1
ER -