EFFECTS OF MECHANICAL LOAD ON CARTILAGE MATRIX BIOSYNTHESIS INVITRO

Cultured bovine articular cartilage full thickness explants were mechanically loaded, both statically and cyclically, at high frequency (2 s of load with 2 s intervals of no load) and low frequency (60 s of load with 60 s intervals of no load), at 1 MPa. Metabolic effects of the load were studied by radiolabeling and compared with non-loaded cartilage explants. High frequency load had a stimulatory effect on protein and proteoglycan synthesis while low frequency and static toad showed decreased synthesis. Removing the load from the cultures restored synthesis to non-loaded control culture levels. No major differences in protein biosynthetic pattern were revealed, as determined by SDS-PAGE and fluorography, showing the generalized nature of the response.