Prevention of skeletal muscle insulin resistance by dietary cod protein in high fat-fed rats.
In the present study, we tested the hypothesis that fish protein may represent a key constituent of fish with glucoregulatory activity. Three groups of rats were fed a high-fat diet in which the protein source was casein, fish (cod) protein, or soy protein; these groups were compared with a group of chow-fed controls. High-fat feeding led to severe whole body and skeletal muscle insulin resistance in casein- or soy protein-fed rats, as assessed by the euglycemic clamp technique coupled with measurements of 2-deoxy-D-[(3)H]glucose uptake rates by individual tissues. However, feeding cod protein fully prevented the development of insulin resistance in high fat-fed rats. These animals exhibited higher rates of insulin-mediated muscle glucose disposal that were comparable to those of chow-fed rats. The beneficial effects of cod protein occurred without any reductions in body weight gain, adipose tissue accretion, or expression of tumor necrosis factor-alpha in fat and muscle. Moreover, L6 myocytes exposed to cod protein-derived amino acids showed greater rates of insulin-stimulated glucose uptake compared with cells incubated with casein- or soy protein-derived amino acids. These data demonstrate that feeding cod protein prevents obesity-induced muscle insulin resistance in high fat-fed obese rats at least in part through a direct action of amino acids on insulin-stimulated glucose uptake in skeletal muscle cells.
Lavigne
C
C
Nutraceuticals and Functional Foods Institute, Laval University, Ste-Foy, Quebec, Canada G1K 7P4.
Tremblay
F
F
Asselin
G
G
Jacques
H
H
Marette
A
A
D000273:Adipose Tissue / Q000187:drug effects / Q000378:metabolism; D000596:Amino Acids / Q000494:pharmacology; D000818:Animals; D002478:Cells, Cultured; D003847:Deoxyglucose / Q000378:metabolism; D004032:Diet; D004041:Dietary Fats / Q000494:pharmacology*; D004044:Dietary Proteins / Q000494:pharmacology*; D005399:Fishes / Q000378:metabolism*; D005947:Glucose / Q000378:metabolism; D015309:Glucose Clamp Technique; D007333:Insulin Resistance / Q000502:physiology*; D007700:Kinetics; D008297:Male; D018482:Muscle, Skeletal / Q000187:drug effects / Q000378:metabolism / Q000502:physiology*; D009206:Myocardium / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D014409:Tumor Necrosis Factor-alpha / Q000096:biosynthesis
D000596:Amino Acids; D004041:Dietary Fats; D004044:Dietary Proteins; D014409:Tumor Necrosis Factor-alpha; D003847:Deoxyglucose; D005947:Glucose