Insulin-like growth factor I stimulates phospholipid synthesis in renal cortical slices without production of inositol phosphate.
The effects of insulin-like growth factor I (IGF-I) on the metabolism of phospholipids in renal cortical slices were examined using either sodium [32P]orthophosphate or myo-[3H]inositol. IGF-I was found to increase the incorporation of phosphate into phospholipids about 2-3-times above control values, leading to an increase in the concentration of total phospholipid phosphorus of 20% above control value after 1 h of incubation. The increased incorporation of phosphate into phospholipids could be prevented by 10 microM cycloheximide, while with 1 microM TPA (12-O-tetradecanoylphorbol 13-acetate) it could not. Insulin was also found to increase the incorporation of phosphate into phospholipids, but only if its concentration was at least 100-times higher than that of IGF-I. When phospholipids were prelabelled, IGF-I neither decreased the level of 32P in phospholipids nor stimulated the formation of inositol phosphates. The results show that IGF-I stimulates phospholipid synthesis without production of inositol phosphates in renal cortical slices.
Crljen
V
V
Department of Physiology, Faculty of Medicine, University of Zagreb, Yugoslavia.
Banfić
H
H
D000818:Animals; D005260:Female; D007294:Inositol / Q000378:metabolism; D007295:Inositol Phosphates / Q000378:metabolism*; D007328:Insulin / Q000494:pharmacology; D007334:Insulin-Like Growth Factor I / Q000494:pharmacology*; D007672:Kidney Cortex / Q000187:drug effects / Q000378:metabolism*; D007700:Kinetics; D010710:Phosphates / Q000378:metabolism; D010743:Phospholipids / Q000096:biosynthesis*; D051381:Rats; D011919:Rats, Inbred Strains; D013002:Somatomedins / Q000494:pharmacology*; D013403:Sugar Phosphates / Q000378:metabolism*; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology
D007295:Inositol Phosphates; D007328:Insulin; D010710:Phosphates; D010743:Phospholipids; D013002:Somatomedins; D013403:Sugar Phosphates; D007294:Inositol; D007334:Insulin-Like Growth Factor I; D013755:Tetradecanoylphorbol Acetate