| Objective: Local injection of PGE2 Achilles tendon was used to induce rabbit Achilles tendinopathy animal models.The effects of different concentrations of PRP on the expression levels of type ?,type ? collagen gene,TGF-?1 and ?-SMA protein in rabbit Achilles tendinopathy animal models were observed,and PRP repair was discussed.The mechanism and dose-effect relationship of Achilles tendinopathy are used as a theoretical basis for clinical application.Methods: Forty-eight white rabbits from New Zealand were selected as the research subjects of the experiment.The weight of the rabbits was(2.4±0.13)kg.After one week of adaptive feeding,the above 48 rabbits were randomly divided into 7 groups,followed by the control group: Group K(Blank control group),M group(model control group),NS group(normal saline control group);treatment group: A group(2 times the concentration of PRP group),B group(4 times the concentration of PRP group),C group(6 times Concentration PRP group),D group(8-fold concentration PRP group),each group has 6 animals.The remaining 6 were used to collect blood to prepare PRP with different concentrations.Local injection of PGE2 Achilles tendon was used to induce Achilles tendinopathy,and an animal model of rabbit Achilles tendinopathy was established.After the successful model building,the A,B,C,and D groups were injected with 0.2 ml of PRP at a concentration of 2,4,6 and 8 times,respectively,and the NS group was injected with the same amount of normal saline for intervention.The above groups only Make an intervention.The specimens were taken on the 14 th day after the intervention,and the experimental indicators were tested to compare the differences of the experimental indicators in each group.Light microscope observation,q RT-PCR and Western Blot detection methods were used to observe the morphological structure of Achilles tendon tissue,type ? type ? collagen gene in Achilles tendon tissue,and TGF-?1 and ?-SMA protein expression in Achilles tendon tissue.Results:1)Ultrasonic examination results: The blood flow signal on the 14 th day of intervention was significantly improved compared with that on the 7th day.Compared with the M group,the Achilles tendon boundary was clear in the B,C,and D groups,the abnormal blood flow signal was reduced,and the C group performed best,There was no significant difference between A and NS groups.2)Gross observation results of Achilles tendon tissue specimens: The Achilles tendon in group K is shiny,tough,without edema,adhesion,and vascularization;in group M,the Achilles tendon has obvious edema,severe adhesion,and obvious vascularization.Compared with the M group,the edema,adhesion and vascularization of the Achilles tendon in the B,C,and D groups were significantly improved,and the C group had the best Achilles tendon repair effect.3)Observing the morphological structure of the injured Achilles tendon tissue under a light microscope: the Achilles tendon fibers in the K group are arranged evenly,compactly,orderly,and neatly,and the fusiform tendon cells are scattered,which are the morphological manifestations of normal Achilles tendon tissue.Tenocytes in group M were scattered,the nucleus of the surrounding tendon fibers was oval,the tendon fibers were locally ruptured and discontinuous,and there were no inflammatory cells and abnormal new blood vessels. The distribution of cells in the NS group and A group is scattered,the tendon fibers are locally slightly broken,and the break is loose and wavy,and the nucleus is not deformed;the cells in the B and D groups are concentrated,the tendon fibers are slightly wavy,and the tendon cell nucleus is not obvious Deformation: The cells in the Achilles tendon tissue of group C are evenly distributed,the tendon fibers are arranged continuously and neatly,there is no abnormal vascular proliferation,and the nucleus is not deformed.With the increase of PRP concentration,the tendon fibers are arranged more compactly.4)Type I collagen gene expression: Compared with the K group,except for the C group,there was no significant difference.The expression of type ? collagen m RNA in the Achilles tendon tissues of the other groups were all down-regulated(P<0.05).Compared with the M group,there was no significant difference between the NS and A groups,and the B,C,and D groups were all significantly up-regulated(P<0.05).Compared with the NS group,there was no significant difference in the A group,and the B,C,and D groups were all significantly up-regulated(P<0.05).Pairwise comparisons between groups showed no difference in groups B and D,but significant differences in groups A and C(P<0.05).5)Type III collagen gene expression: Compared with the K group,the expression of type ? collagen m RNA in the Achilles tendon tissues of each group increased(P<0.05).Compared with the M group,except for the NS and A groups,there was no significant difference,and the B,C,and D groups were significantly different,and the expression of type ? collagen m RNA was up-regulated(P<0.05).Compared with the NS group,in the A,B,C,and D groups,except for the A group,the expression of type ? collagen m RNA was significantly up-regulated(P<0.05),and the C group was the most up-regulated.Pairwise comparisons between groups showed no significant difference between groups B and D,but significant difference between groups A and C(P<0.05).6)TGF-?1 protein expression: Comparing the M group with the K group,the TGF-?1 protein expression was significantly reduced,and there was a significant difference between the two groups(P<0.05).Compared with group M,the expression of TGF-?1 protein in groups A,B,C,and D all increased,showing a positive correlation with the concentration of PRP.The increase in group D was more significant,and there were differences between groups(P<0.05).7)?-SMA protein expression: Compared with group K,the expression of A,B,M,and NS groups all decreased(P<0.05),there was no significant change in group C,and the expression of group D increased.Compared with the M group,the expression of ?-SMA protein had no significant change except for the NS group,but increased in the A,B,C,and D groups,and was dose-dependent with the PRP concentration,and the difference was statistically significant(P<0.05).Pairwise comparisons between groups showed that there was no significant difference between groups A and B(P>0.05),and there were significant differences between groups C and D(P<0.05).Conclusion:(1)PRP can promote the synthesis of type ? and type ? collagen fibers in animal Achilles tendinopathy models.(2)PRP can regulate the expression of ?-SMA protein by releasing TGF-?1 to promote the repair of Achilles tendinopathy.(3)PRP promotes the repair of Achilles tendinopathy and is closely related to the concentration,and the repair effect is better with a concentration of about 6 times. |
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