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.
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.
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.
Cyclic tensile strain loaded on the chondrocytes enhanced NO synthesis and this enhanced NO inhibited PG synthesis.