The Effects Of Eight Weeks Treadmill Training On The Femoral Maximum Load And Leptin Signal Pathway In Marrow Of Obese Rats Aged

Objective:The research object of this study were2615-month-old female SD rats,this paperresearched the effects of aerobic exercise on femoral maximum load and Leptin signalpathway in femoral marrow of obese rats aged.It provided the experience basis forresearch of Leptin adjusting bone metabolism,and the theory basis for prevention senileosteoporosis on exercise.Methods:1.28rats were randomly divided into2groups: the Normal control group（n=8）andthe Obese group（n=20）.The Obese group rats were treated with High﹣Fat Diet,Eliminate2obesity resistance,the obesity model was established，the Obese group ratswere randomly divided into2groups: the Obese control group（n=9） and the Obeseexperimental group（n=9）.The weight of two groups was not significant difference.2.Exercise interventions:The Obese experimental group rats were in treadmill trainingfor8weeks by the way increasing load movement.The initial exercise time was10min/d,and the seventh week increased to90min/d,this time last to the end of eighthweek;Theinitial velocity was10m/min, the fifth week increased to20m/min, this velocity last tothe end of eighth week.3.Test indicators:We took tissue after24hours from the end of the last movementof the obese experimental group (12hours of fasting).Took the right femurs of hindlegs to test maximum load with3-point bending test.Took the left femurs of hind legsto test leptin,OB-Re and OB-Rb, JAK2and STAT3in femoral marrow with WesternBlot.Results:1.Before exercise intervention, the body weight of the Obesity group rats wasSignificantly increased than the Normal control group（P﹤0.001）,The weight of Obesitygroup rats was increased20%than average body weight of the Normal control grouprats.There was not significant difference between the weight of the Obese control grouprats and the Obese experimental group（P﹥0.05）;After exercise intervention, comparedwith the Normal control group, body weight,the total weight of abdominal fat and the total weight of abdominal fat/weight ratio of Obese control group rats, were significantly increased（all P﹤0.001）.Compared with the Obese control group, the total weight ofabdominal fat and the total weight of abdominal fat/weight ratio of the Obeseexperimental group rats were significantly declined（P﹤0.05，P﹤0.05）.2.Compared with the Normal control group,the maximum load that femurs of theObese control group rats could withstand was not significant differencethere was nostatistical significance（P﹥0.05）,but the body weight/load ratio was significantlyincreased(P﹤0.01）;Compared with the Obese control group,the maximum load thatfemurs of the obese experimental group rats could withstand was significantly increased（P﹤0.05）,but the body weight/load ratio was significantly declined（P﹤0.05）.3.Compared with the Normal control group, the levels of leptin, JAK2and STAT3were increased,the levels of OB-Re and OB-Rb were decreased, but there was notsignificant difference in femoral marrow of the Obese control group rats, there was nostatistical significance（all P﹥0.05）;Compared with the Obese control group, the levelsof leptin and OB-Rb were increased,the JAK2levels was decreased,but there were not significant difference, there was no statistical significance（all P﹥0.05）,the levels ofOB-Re and STAT3were significantly increased in femoral marrow of the Obeseexperimental group rats（P﹤0.05,P﹤0.05）.Results:1.The femoral biomechanical performances of rats aged was not significant influence，that might be correlated with that the effects of leptin JAK2/STAT3signal pathwaytransduction in femoral marrow was not significant influence,but weight gain increasedthe risk of femoral fractures.2.Aerobic exercise improved the femoral biomechanical properties of obese ratsagedand the risk of femoral fractures declined, guess the effects of leptin JAK2/STAT3pathway transduction strengthen might be one of mechanisms improving femoralbiomechanical performances on exercise.