In vitro rabbit articular cartilage organ model II. ³⁵S incorporation in various oxygen tensions

Adult rabbit articular cartilage slice and plug explants were cultured in MEM/NCTC 109/fetal calf serum at 37°C in various oxygen tensions. In both the slice and plug explants, 35 SO 4 incorporation exhibited a broad tolerance to oxygen tensions varying from 5 (38 mm. Hg) to 60 (456 mm Hg) per cent. Significantly ( P 0.01) less 35 SO 4 was incorporated in 1 (7.6 mm Hg) and 90% (684 mm Hg) oxygen than in 21% (160 mm Hg) oxygen. No histologic or autoradiographic differences, and only slight histochemical differences, were discernible after seven days culture in the various oxygen tensions. It is suggested that low synovial fluid oxygen tension is detrimental to articular cartilage glycosaminoglycan metabolism.