Porcine insulin-like growth factor (IGF) binding protein blocks IGF-I action on porcine adipose tissue.
A growth hormone-dependent insulin-like growth factor (IGF) binding protein (IGFBP) purified from porcine serum specifically blocked the acute insulin-like effects of IGF-I on lipogenesis and glucose oxidation in porcine adipose tissue. This inhibition was dose dependent with half-maximal effective concentrations of IGFBP of 530 ng/ml for lipogenesis and 590 ng/ml for glucose oxidation in the presence of 10(-8) M IGF-I. The IGFBP also caused decreased rates of lipogenesis following a 1-hr preincubation of tissue with IGF-I (10(-8) M). The IGFBP had no effect on insulin action on porcine adipose tissue. These findings demonstrate the inhibitory effects of a highly purified porcine serum IGFBP on the biologic effects of IGF-I in vitro, and provide evidence that the growth hormone-dependent IGFBP blocks the acute insulin-like actions of IGF-I in vivo.
Walton
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PE
Department of Dairy and Animal Science, Pennsylvania State University, University Park 16802.
Gopinath
R
R
Etherton
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TD
D000273:Adipose Tissue / Q000187:drug effects* / Q000378:metabolism; D000818:Animals; D001667:Binding, Competitive; D002352:Carrier Proteins / Q000502:physiology*; D005947:Glucose / Q000378:metabolism; D007328:Insulin / Q000494:pharmacology; D018969:Insulin-Like Growth Factor Binding Proteins; D007334:Insulin-Like Growth Factor I / Q000494:pharmacology*; D008055:Lipids / Q000096:biosynthesis; D013002:Somatomedins / Q000378:metabolism* / Q000494:pharmacology*; D013552:Swine
D002352:Carrier Proteins; D007328:Insulin; D018969:Insulin-Like Growth Factor Binding Proteins; D008055:Lipids; D013002:Somatomedins; D007334:Insulin-Like Growth Factor I; D005947:Glucose