The effect of hyperoxia on pig articular tissue has been studied in organ culture. Hyperoxia (55% O2) causes an increased release of hydroxyproline and collagenolytic activity from synovial tissue as compared with control explants in 20% O2, but neither 55% nor 95% O2 has any effect on the breakdown of isolated cartilage during 10 days in culture. When synovium and cartilage are cultured in con...