The lipolytic activity of low concentrations of insulin-like growth factors in ovine adipose tissue.
Insulin-like growth factor I (IGF-I) at concentrations of 40 ng/ml is lipogenic in ovine adipose tissue slices in vitro. Neither human IGF-II (hIGF-II) or rat IGF-II (rIGF-II) [multiplication-stimulating activity (MSA)] is lipogenic at similar concentrations. However, when present at lower concentrations recombinant human IGF-I (rhIGF-I) (400 pg/ml), hIGF-II (0.4 pg/ml), and MSA (40 pg/ml) were lipolytic. As IGF-II appeared more potent than IGF-I in promoting lipolysis, this effect may be mediated via the type 2 IGF receptor. The lipolytic effect of GH may be partly due to the actions of IGFs released locally.
Lewis
K J
KJ
Department of Biological Sciences, University of Waikato, Hamilton, New Zealand.
Molan
P C
PC
Bass
J J
JJ
Gluckman
P D
PD
D000273:Adipose Tissue / Q000187:drug effects / Q000378:metabolism*; D000818:Animals; D004837:Epinephrine / Q000494:pharmacology; D005990:Glycerol / Q000378:metabolism; D013006:Growth Hormone / Q000494:pharmacology; D007334:Insulin-Like Growth Factor I / Q000494:pharmacology*; D007335:Insulin-Like Growth Factor II / Q000494:pharmacology*; D007700:Kinetics; D008055:Lipids / Q000096:biosynthesis; D008066:Lipolysis / Q000187:drug effects*; D008297:Male; D011994:Recombinant Proteins; D012756:Sheep; D013002:Somatomedins / Q000494:pharmacology*
D008055:Lipids; D011994:Recombinant Proteins; D013002:Somatomedins; D007334:Insulin-Like Growth Factor I; D007335:Insulin-Like Growth Factor II; D013006:Growth Hormone; D005990:Glycerol; D004837:Epinephrine