Effects of Exercise on Bone Metabolism and Biomechanical Index in Aged Mice

The purpose of this study was to discuss the effects of exercise on the tissue structure and function and related to aging.Forty sanitary male KM mice aged at twelve months were randomly divided into four groups:Aged control group,exercise group with ten minutes,exer-cise group with twenty minutes and exercise group with forty minutes.All of groups were carried on twelve weeks exercise.Ten mice aged at three month and ten mice aged at seven month were taken as junior and senior control group respectively.Bone mineral density (BMD) and biomechanical index were measured by using the solid physic density instrument and biomechanical instrument respectively.Main biomechanical index included maximal load and stress,modulus and energy.The result showed that comparing with aged control group,there was no significant difference on ALP in each exercise group.The level of BMD was high in exercise group with ten and twenty minutes respectively.Maximal load,stress and modulus were significantly higher in junior and adult control group than that of aged control group respe-ctively.Comparing with aged control group,maximal load and stress,modulus and energy supply were higher in exercise group with twenty minutes.It concluded that suitable intensity swimming training could improve bone mineralization.The effects of exercise on biomechanical index of bone related to exercise intensity and suitable intensity exercise could improve the synthetic function of bone biomechanics.Less or more exercise intensity could not win a good effect.The suitable exercise intensity was benefit to structure,function and metabolism of bone tissue.These benefits played a good role in the retard of cell aging and function degradation of bone.