The effects of insulin and insulin-like growth factor I (IGF-I) on protein synthesis were compared in muscle isolated from lean and goldthioglucose (GTG)-obese mice. Two types of skeletal muscles, the red soleus and the white extensor digitorum longus (EDL) muscles, were studied. In muscles from lean mice, 6.7 nM insulin and 50 nM IGF-I caused a similar maximal stimulationof tyrosine incorporation in total proteins (40% increase). However, the potency of IGF-I was only 5–10% that of insulin both in soleus and in EDL muscles (EC50 ≅ 6 nM for IGF-Iand 0.5 nM for insulin). Basal rate of protein synthesis was identical in muscles from GTG-obese and lean mice. Similarly, a comparable increase in the rate of protein synthesis was obtained using maximally effective concentrations of insulin and IGF-I in both lean and GTG-obese animals. SDS-polyacrylamide gel electrophoresis analysis of proteins labeled with 35S-methionine confirmed that, in muscles from lean and GTG-obese animals, insulin and IGF-I increased overall protein synthesis in a similar manner. These results suggest that the protein synthesis machinery is not impaired in GTG-induced obesity, which is therefore not associated with resistance to insulin for its effect on protein metabolism.
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May 01 1983
Insulin and Insulin-like Growth Factor I: Effects on Protein Synthesis in Isolated Muscles from Lean and Goldthioglucose-Obese Mice
Solange Monier;
Solange Monier
Unité de Recherches sur les Hormones Polypeptidiques et la Physiopathologie Endocrinienne, Institut National de la Santé et de la Recherche Médicale (I.N.S.E.R.M.), Unité U 145, Laboratoire de Médecine Expérimentale
Faculté de Médecine, 06034 Nice Cedex, France
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Alphonse Le Cam;
Alphonse Le Cam
Unité de Recherches sur les Hormones Polypeptidiques et la Physiopathologie Endocrinienne, Institut National de la Santé et de la Recherche Médicale (I.N.S.E.R.M.), Unité U 145, Laboratoire de Médecine Expérimentale
Faculté de Médecine, 06034 Nice Cedex, France
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Yannick Le Marchand-Brustel
Yannick Le Marchand-Brustel
Unité de Recherches sur les Hormones Polypeptidiques et la Physiopathologie Endocrinienne, Institut National de la Santé et de la Recherche Médicale (I.N.S.E.R.M.), Unité U 145, Laboratoire de Médecine Expérimentale
Faculté de Médecine, 06034 Nice Cedex, France
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Address reprint requests to Dr. Yannick Le Marchand-Brustel, INSERM U 145, Faculté de Médecine (Pasteur), Chemin de Vallombrose, 06034 Nice Cedex, France.
Citation
Solange Monier, Alphonse Le Cam, Yannick Le Marchand-Brustel; Insulin and Insulin-like Growth Factor I: Effects on Protein Synthesis in Isolated Muscles from Lean and Goldthioglucose-Obese Mice. Diabetes 1 May 1983; 32 (5): 392–397. https://doi.org/10.2337/diab.32.5.392
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