The Expression And Significance Of Bcl-2, Bax Protein And Chondrocyte Apoptosis In Limb Ischemia-reperfusion Injury

Objective:To observe the dynamic expression of Bcl-2 and Bax protein and chondrocyte apoptosis in a rat limb ischemia-reperfusion injury model.To explore the mechanism of Bcl-2 and Bax protein on the apoptosis of articular cartilage in LIRI.Methods:Fourty SD rats were used and divideded into 8 groups at random:Control group,ischemia group,ischemia-reperfusion groups(1,3,7, 14,30,60d).Each group has 5 rats.Rats limb ischemia-reperfusion injury model was established from Chengjianchang'method.The grouped rats were killed respectively.The articular cartilage were excised from the medial of the left keen joint and were fixed in 4%paraformaldehyde for 24h,then paraffin section were made.The paraffin sections were analyzed by immunohistochemistry for bcl-2 and bax,TUNEL for apoptosis.All dates were expressed as mean±SEM.In the end,we analysed the outcomes of this experiments with SPSS13.0.Vaue of p＜0.05 were considered statistically significance.Results:1.No positive apoptotic cells was observed in the control group and a litte(3.44±1.17)of that were seen in the ischemia group.The number of apoptotic cells increased with the development of reperfusion within 7days and reached peak(24.36±2.24) at 7d.Then the number began to decrease,and there were significant difference between IR 60d group and control group(P＜0.01)2.No obvious positive reactive products of Bcl-2 was seen in the control group while positive reactive product of bcl-2 were seen in IR 6h group.And peaked at 3 day,the grey scacle was(93.30±7.55).Then decreased in 7d-60d,with the grey scacle by(106.02±7.73),(117.34±9.15),(127.58±10.92) and(130.14±9.19).there were significant difference between IR groups and control group.3.No obvious positive reactive products of Bax was seen in the control group,the grey scacle was(139.68±7.15).Bax in IR groups expressed gradually higher with time passed,and peaked at IR 7d,the grey scacle was(82.00±8.58).Then the positive reactive products of Bax began to decrease,and there were signifycant difference between IR groups and control group(P＜0.01).4.Pearson's correlation analysis showed that the number of chondrocyte apoptosis was positively correlated with Bcl-2/Bax ratio of the grey scacle(P＜0.05) and the correlation coefficient was 0.876,except the IR 3d group.Conclusion:1.Apoptosis is a mechanism for the injury of articular cartilage in limb ischemia-reperfusion.2.Bcl-2,Bax participates in regulating the hondrocyte apoptosis during limb ischemia-reperfusion inury.3.the change of Bcl-2/Bax ration may be a mechanism for hondrocyte apoptosis during limb ischemia-reperfusion inury.