Effects Of Jumping Load On Histology And Apoptosis In Rabbit Patella-patellar Tendon Junction

Objective: To observe the pathological changes and cell apoptosis of rabbit patella-patellar tendon junction injury under different jump load accumulation by jumping training.The histological changes of rabbit patella-patellar tendon junction and the effect of apoptosis,in order to explore the mechanism of injury to provide a theoretical basis.Methods: Twenty female New Zealand white rabbits were divided into two groups: 2 weeks,4 weeks,6 weeks,8 weeks and control group.Using jumping device for jump training,jump 5 days a week,jump 150 times a day,mechanical test per week,get active takeoff and free landing peak power.After the corresponding number of weeks of jump training,the rats were sacrificed,routine histological treatment,H & E,Safranin O and immunohistochemical staining.Meta Morph Premier was used to measure the density of the patella-patellar tendon junction,the thickness of fibrocartilage,Protein area and other indicators of tissue morphology measurement,immunohistochemical assessment of apoptotic cells positive staining cell density.The significance level was P <0.05.Results: The jump training method used in the experiment can make the rabbit get a stable load.2W and 4W group were significantly higher than those in CON group.The cell density of 6W group was significantly lower than that of 2W group,the cell density of 8W group was significantly lower than that of 2W group,and the cell density of 6W and 8W group was significantly lower than that of 4W group.The thickness of fibrous cartilage was significantly higher than that of CON group,and the thickness of fibrous cartilage in 6W group was significantly higher than that in 2W group.The thickness of fibrous cartilage in 8W group was significantly lower than that in 6W group.The expression of mucopolysaccharide protein in 4W and 6W group was significantly higher than that in CON group Compared with the CON group,the expression of Caspase-3 in the 6W group was significantly higher than that in the control group(P <0.05),and there was significant difference between the two groups The expression of Caspase-3 in 8W group was significantly lower than that in 2W group,which was significantly lower than that in4W and 6W groups.Conclusion: The 6-week jumping accumulation can make the histological and apoptotic changes of the patella-patellar tendon junction,and 6 weeks is the important time node of this jump model.The jump load can cause the patella-patellar tendon junction cells sustained over-apoptosis,cell over-apoptosis and lack of proliferation are reasons of the mechanisms that caused patella-patellar tendon junction injury.