Effects of static pressure on apoptosis of chondrocytes and the PCNA expression

Objective To investigate the effects of static pressure on apoptosis and proliferation of condrocytes and the correlation between IL-1β and TNF-α and the apoptosis of ehondroeytes. Methods The chondrocytes of rabbits were cultivated in different static pressure conditions (20,40,70 kp) for different durations (0,4,16,24 h) respectively,then the cells were collected. The apoptosis of chondrocytes was assayed by FCM. The expression of PCNA was detected. The IL-113 and TNF-a of culture meditun were evaluated at same time. Results The apoptosis of ehondrocytes was increased after mechanical stimuli whatever its magnitude. With prolongation of time,the apoptosis index had different changes (P ＜ 0.05). The proliferation were inhibited at first 4 hours ( P ＜ 0.05 ), and then inereased rapidly after the following time. TNF-αtwas increased with the time lasting at 40 kp and 70 kp, and it correlated to chondrocyte apoptosis. The IL-1 [3was decreased with the time lasting at 70 kp, and it negative correlated apoptosis of chondrocyte,we also found the IL-1βdecreased when enhanced pressure on 24 h and it correlated the PCNA express at 24 h. Conclusion So we could conclued that the number of chandrocytes were decreased at high static pressure and long effect time. Key words: Chondrocyte;  Mechanics;  Apoptosis