Expression Of Collagen And Related Growth Factor In Juvenile Rat’s Achilles Tendon In Response To HIIT

Purpose:this paper studies the high intensity intermittent training after the completion of the training of juvenile rat Achilles tendon Ⅰ collagen fiber,Ⅲ collagen fibers,and change of TGF-betal,explore whether high-intensity intermittent training could be beneficial for minor individual tendons,then provide a reference for youth sports training significance.Mehods:Fifty four-week-old male SD rats were randomly divided into a blank control group(E,10);Experimental group A(10),B(10),C(10),and D(10).After adaptability training of 3 days loaded with 12-25m/min speed and 2 days loaded with 25-45m/min speed,insisting 30 mins per day.we tested VO2max of each group at the 6th day.After that,the experimental groups take a 4-week,5-day-per week atheleting intervene which uses 10°slope technogym,exercising 10 times per day with 1 minute working and 2minutes relaxing,loaded with intensity that group A using 90%vVO2max,group B using 120%vVO2max,group C using 150%vVO2max,group D using 180%vVO2max.After each session,the rats returned to the cages for rest,and 24 hours after the end of the last session,the rats were sacrificed for the Achilles tendon.the paraffin sections were stained with H&E dyeing for structral observation,and immunohistochemical treatment for Semi-quantitative detection of COL-Ⅰ、COL-Ⅲ and TGF-β1 content using AOD analysed by computer software.Results:(1)Among all groups,it shows no Pathological abnormality under H&E staining within tendon tissues.(2)Compared with group E,COL-Ⅰ concentrations in group A and Group B were significantly increased(P<0.05),while COL-Ⅲconcentrations were significantly decreased(P<0.05).TGF-1 concentration in group A,B,C and D was not higher than that in group E(P<0.05).Conclusion:(1)High-intensity interval training with 90%vVO2max and 120%vVO2max intensity during the 4-week period benefit the collagen of Achilles tendon in young rats.(2)High-intensity interval training with 150%vVO2max and 180%vVO2max intensity during the 4-week period did not have the positive effect on the collagen of Achilles tendon in young rats.(3)The HIIT method in this research can’t lead to high risk of tendinopathy of young rats’ Achilles tendon,regarding Achilles tendon protection,90%、120%、150%、180%vVO2max are all adequate for intensity of juvenile rats HIIT.