Study of chondrocyte apoptosis after impacting injury of articular cartilage

[Objective]To observate the successive status of chondrocyte apoptosis after impacting injury of articular cartilage by TUNEL marking method and transmission electron microscope(TEM).[Method]Fifty-six New Zealand adult rabbits were divided randomly into low-energy and high-energy two groups,each group was 28.Femoral medial condylar cartilage of one side was injuked by impacting in experimental group,the opposite side as control group.Four rabbits were killed and their medial femoral condylar cartilages were taken at each of the following intervals:4 days,1,2,4,8,16,32 weeks after impacting injury.The specimens were observed as pathology histological sections and strained by TUNEL to measured the rate of chondrocyte apoptosis.[Result]In early stage of post-injury,the rate of chondrocyte apoptosis in and high-energy is significantly higher than that of control group.After 4 weeks,the rate of chondrocyte apoptosis decreases to the level of that of control group in low-energy.In high-energy group,the rate of chondrocyte apoptosis is constantly upgraded-phase,higer significantly than the level of that of control group.[Conclusion]In early stage of post-injury,the rate of chondrocyte apoptosis in low and high-energy was significantly higher than that of control group.After 4 weeks,the rate of chondrocyte apoptosis decreased to the level of control group in low-energy.In high-energy group,the rate of chondrocyte apoptosis is constantly upgraded-phase,higer significantly than the level of control group.