Enhancement of nitric oxide and proteoglycan synthesis due to cyclic tensile strain loaded on chondrocytes attached to fibronectin.
OBJECTIVE
Mechanical stress is an essential factor in the pathogenesis of osteoarthrosis. We sought to determine whether the strain-mediated alteration in proteoglycan (PG) synthesis was modulated by nitric oxide (NO) synthesis.


METHODS
Cyclic tensile strain was applied to bovine articular chondrocytes. PG and NO synthesis were determined by [35S] sulfate incorporation and chemiluminescence analysis, respectively. To determine the expression of inducible NO synthase (iNOS), quantitative RT-PCR was used.


RESULTS
Enhanced PG and NO synthesis were evident when cyclic tensile strain was applied to chondrocytes seeded on fibronectin-coated plates. When NO production was inhibited, PG synthesis was further enhanced.


CONCLUSIONS
Cyclic tensile strain loaded on the chondrocytes enhanced NO synthesis and this enhanced NO inhibited PG synthesis.
Matsukawa
M
M
Department of Orthopaedic Surgery, Kinki University School of Medicine, Ohnohigashi 377-2, Osaka-sayama, Osaka 589-8511, Japan.
Fukuda
K
K
Yamasaki
K
K
Yoshida
K
K
Munakata
H
H
Hamanishi
C
C
D000818:Animals; D002356:Cartilage / Q000378:metabolism; D002417:Cattle; D002448:Cell Adhesion; D019902:Chondrocytes / Q000378:metabolism*; D004247:DNA / Q000378:metabolism; D017931:DNA Primers / Q000737:chemistry; D004305:Dose-Response Relationship, Drug; D005353:Fibronectins / Q000378:metabolism*; D007632:Keratan Sulfate / Q000378:metabolism; D009569:Nitric Oxide / Q000096:biosynthesis*; D019001:Nitric Oxide Synthase / Q000096:biosynthesis; D052247:Nitric Oxide Synthase Type II; D009841:Oligonucleotides / Q000737:chemistry; D010003:Osteoarthritis / Q000378:metabolism; D011509:Proteoglycans / Q000096:biosynthesis* / Q000378:metabolism; D012333:RNA, Messenger / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013314:Stress, Mechanical; D013431:Sulfates / Q000378:metabolism; D013997:Time Factors
D017931:DNA Primers; D005353:Fibronectins; D009841:Oligonucleotides; D011509:Proteoglycans; D012333:RNA, Messenger; D013431:Sulfates; D009569:Nitric Oxide; D004247:DNA; D007632:Keratan Sulfate; D019001:Nitric Oxide Synthase; D052247:Nitric Oxide Synthase Type II