Effects of Exercise Preconditioning on the Blood IL-6 in Rats after Eccentric Exercise

Objective:To observe the effects of Exercise Preconditioning on muscle damage at different phases after eccentric exercise and change of blood IL-6.Methods:Eighty SD rats were randomly divided into control group(group A,n=40),and experiment group(group B,n=40).All rats of group B were forced to have treadmill exercise for two weeks.After two weeks,once treadmill(19-21m/min,-16°,90min) test was made for rats.After exercise,soleus muscle was obtained and blood sample were elicited from femoral artery.The fibrous structure and changes of the blood IL-6 were observed.Results:(1) The ultrastructure of skeletal muscle in two groups changed obviously.The changes were more serious at 24h-48h after exercise than other phases.The changes in group B was milder than that in group A.(2) Plasm IL-6 of group A increased significantly in instant,whereafter kept on decreasing,and increased significantly again in 72h.The peak value of IL-6 appears in 48h at group B.IL-6 of group A was obviously higher than that of group B after exercise.Conclusion:Exercise preconditioning redounded to lightening the muscle injury induced by eccentric exercise.It can restrain the enhancement of plasm IL-6.Results also indicated that IL-6 could be an important index for determining skeletal muscle damage.