The Effects Of Endurance Training On The Genic Expression Of GLUT4,PDK4 And AMPKα2 In High-Fat Feeding Rat Skeletal Muscle

Glucose and fat play an important role in fuel supply and integration of energy metabolism.In normal state,glucose and fat metabolism is under strict regulation and control,but many factors can affect the body's precise control,such as high-fat diet and exercise.Usually,these factors can produce a profound impact on the body's blood glucose metabolism and fatty acid intake.When the energy supply and metabolism are abnormal,the normal activities of life are bound to be threatened.Accordingly,the ability to utilize substrate of the body is very important for survival.Skeletal muscle is the major tissue for glucose uptake and utilization,but peripheral insulin resistance also occur in it.So to reduce insulin resistance in skeletal muscle has become a new way of treatment for type 2 diabetes.Of the many prevention and treatment of insulin resistance,exercise has always been of concern. Exercise can promote glucose transport and utilization in skeletal muscle independent of the insulin pathway,and improve insulin sensitivity.Also exercise can influence the gene expression of glucose and lipid metabolism and optimize the overall energy metabolism in order to prevent insulin resistance and keep healthy.Objective:To investigate the effects of endurance training on blood glucose,plasma insulin levels,and the genic expresstion GLUT4,PDK4 and AMPKα2 in high-fat feeding rat skeletal muscle.Methods:Total 40 male SD rats were randomly divided into four groups which include control group feeding with maintenance diet(C),endurance training group feeding with maintenance diet(E),control group feeding with high fat diet(H),endurance training group feeding with high fat diet(R).There are 10 rats in each group.E and R groups were trained on the treadmill for 8 weeks.6 times a week,in the initial four weeks,they exercise 40 minutes every time,and the last four weeks,they exercise 60 minutes every time.The rats were killed in the time during 24～48 hours after the last time exercise.Detected the blood glucose and plasma insulin levels in each group,the situation of insulin resistance were reflected by insulin resistance index.mRNA levels of GLUT4,PDK4 and AMPKα2 of rats'skeletal muscle were determined using real-time PCR.Protein contents of PDK4 and P-AMPKα2 in rats' skeletal muscle were measured using western blot. Results:(1)High-fat diets obviously increased rats's body weight growth rate,the level of blood glucose and insulin resistance index.Endurance training have a positive effection on the Situations that induced by high-fat diets.(2)Neither high-fat diets nor it combined with endurance training did not induce a significant change of GLUT4 mRNA levels in rats's skeletal muscles.(3)High-fat diets induced a significant increase of PDK4mRNA levels in rats' skeletal muscles(p＜0.01),but did not change the protein content of PDK4.Endurance training increased the expression PDK4mRNA under the condition of high-fat diets,but also had no effection on the the protein content of PDK4.(4)High-fat diets did not induce a significant increase of AMPKα2 mRNA levels in rats's skeletal muscles,but it could increased protein levels of P-AMPKα2 in the rats's skeletal muscle of control group feeding with high fat diet(p＜0.01),compared with control group feeding with maintenance diet.Endurance training had no effection on the levels of P-AMPKα2 in the rats's skeletal muscle of endurance exercise group feeding with high fat diet.Conclusions:(1) High-fat diets have a negative impact on the level of blood glucose and insulin sensitivity.High-fat diet combined with endurance training can significantly delay the occurrence of the phenomenon,shows that endurance training can improve the body's insulin sensitivity,and decrease blood glucose.(2) High-fat diet imposed metabolic stress on the body,endurance training may increase energy consumption,or to optimize the use of substrates,to enhance the integration of energy metabolism,and thus alleviate the metabolic stress that caused by high-fat diet,and promote the stability of the body's energy metabolism.