Exercise and diet reduce muscle insulin resistance in obese Zucker rat.
Two treatments that increase skeletal muscle insulin action are exercise training and high-carbohydrate diet. The purpose of the present study was to determine whether exercise training and a diet high in carbohydrates could function synergistically to reduce the muscle insulin resistance in the obese Zucker rat. Obese rats 4 wk of age were randomly assigned to an exercise or sedentary group. Each group was subdivided by diet with one-half of the rats fed a high-carbohydrate diet and one-half fed a high-fat diet. Lean Zucker rats fed the high-fat diet were used as controls. Muscle insulin resistance was assessed during hindlimb perfusion with a submaximally stimulating concentration of insulin. Exercise training and the high-carbohydrate diet increased the rate of muscle glucose uptake in the obese rat by 46 and 53%, respectively. More importantly, the combined effect of exercise training and high-carbohydrate diet was greater than the sum of their individual effects. Glycogen synthesis paralleled glucose uptake and was the major pathway for intracellular glucose disposal. Muscle glucose uptake for exercise-trained, high-carbohydrate fed obese rats was comparable with that of lean controls. It is concluded that exercise training and the high-carbohydrate diet functioned synergistically to reduce the muscle insulin resistance in the obese rat.
D000818:Animals; D004040:Dietary Carbohydrates / Q000627:therapeutic use*; D005947:Glucose / Q000378:metabolism; D006003:Glycogen / Q000096:biosynthesis; D006593:Hexokinase / Q000378:metabolism; D007333:Insulin Resistance; D007773:Lactates / Q000096:biosynthesis; D019344:Lactic Acid; D009132:Muscles / Q000378:metabolism*; D009765:Obesity / Q000178:diet therapy / Q000503:physiopathology* / Q000628:therapy; D010084:Oxidation-Reduction; D010805:Physical Conditioning, Animal; D051381:Rats; D011924:Rats, Zucker
D004040:Dietary Carbohydrates; D007773:Lactates; D019344:Lactic Acid; D006003:Glycogen; D006593:Hexokinase; D005947:Glucose