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Calorie Restriction Increases In Vivo Glucose Uptake and Insulin Signaling in Rat Skeletal Muscle
Author(s) -
Sequea Donel Angelo,
Sharma Naveen,
Castorena Carlos M,
Qi Nathan,
Cartee Gregory D
Publication year - 2011
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.25.1_supplement.lb591
Subject(s) - medicine , endocrinology , insulin , skeletal muscle , insulin receptor , protein kinase b , glucose uptake , calorie restriction , glucose clamp technique , insulin resistance , chemistry , irs1 , pancreatic hormone , phosphorylation , biology , biochemistry
Calorie restriction (CR; eating ~60% of ad libitum, AL, intake) enhances insulin‐mediated glucose uptake (GU) and Akt phosphorylation in isolated rat skeletal muscle. The aim of this study was to determine if CR (6mo duration begun at 3mo‐old) also improves in vivo glucose uptake and Akt phosphorylation in skeletal muscle of male, Fischer 344 Brown Norway rats undergoing a euglycemic‐hyperinsulinemic clamp. Glucose and insulin were infused to achieve similar plasma values for glucose (119±2mg/dl for AL and 119±5mg/dl for CR) and insulin (161±9μU/ml for AL and 156±8μU/ml for CR) in the 2 groups. Glucose infusion rate (mg/kg/min) of the CR group (33 ±2) was significantly higher than the AL group (16 ±1), and radiolabeled 2‐deoxyglucose uptake (μg/g/min) was also significantly increased for the epitrochlearis muscle of CR (24 ±2) vs. AL (14 ±1) rats. CR vs. AL group had greater values for pS473‐Akt and pT642‐Akt substrate of 160 kDa (AS160), but not for pY1162/1163‐insulin receptor in insulin‐stimulated epitrochlearis. The enhanced whole body insulin sensitivity in CR vs. AL rats was likely attributable, at least in part, to elevated insulin‐mediated GU of skeletal muscle secondary to enhanced pS473‐Akt and pT642‐AS160 despite unaltered pY1162/1163‐insulin receptor. Support: NIH (R01‐AG10026 and T32‐ AG000114 ).