| Full text | |
| Author(s): |
Barbosa, Thais de Castro
[1, 2, 3]
;
Jiang, Lake Q.
[2, 3]
;
Zierath, Juleen R.
[2, 3]
;
Nunes, Maria Tereza
[1]
Total Authors: 4
|
| Affiliation: | [1] Univ Sao Paulo, Inst Ciencias Biomed, Dept Physiol & Biophys, BR-05508 Sao Paulo - Brazil
[2] Karolinska Inst, Dept Mol Med & Surg, Sect Integrat Physiol, S-17177 Stockholm - Sweden
[3] Karolinska Inst, Dept Mol Med & Surg, Sect Integrat Physiol, Stockholm - Sweden
Total Affiliations: 3
|
| Document type: | Journal article |
| Source: | METABOLISM-CLINICAL AND EXPERIMENTAL; v. 62, n. 1, p. 79-89, JAN 2013. |
| Web of Science Citations: | 15 |
| Abstract | |
Objective. The amino acid Arginine (Arg) is the main biological precursor of nitric oxide (NO) and has been described to improve insulin sensitivity in diabetes and obesity. We investigated the molecular mechanisms involved in the long-term effects of Argon glucose and lipid metabolism. Materials and Methods. L6 myotubes were treated with Arg (7 mmol/L) for 6 days. D-Mannitol (7 mmol/L) was used as control; spermine NONOate (10 mu mol/L) and L-NAME (100 mu mol/L) were used to evaluate the NO/c-GMP pathway role. Basal and insulin-induced (120 nmol/L) glycogen synthesis, glucose uptake and lipid oxidation, c-GMP and nitrite levels, and the intracellular signaling pathways were evaluated. Results. Arg-treatment increased: 1) basal and insulin-stimulated glycogen synthesis; 2) glucose uptake; 3) palmitate oxidation; 4) p-Akt (Ser(473)), total and plasma membrane GLUT4 content, total and p-AMPK-alpha and p-ACC (Ser(79)), p-GSK-3 alpha/beta (Ser(21/9)) and 5) nitrite and c-GMP levels. L-NAME treatment suppressed Arg effects on: 1) nitrite and c-GMP content; 2) glycogen synthesis and glucose uptake; 3) basal and insulin-stimulated p-Akt (Ser(473)), total and p-AMPK-alpha and ACC, and nNOS expression. Conclusion. We provide evidence that Mg improves glucose and lipid metabolism in skeletal muscle, in parallel with increased phosphorylation of Akt and AMPK-alpha. These effects were mediated by the NO/c-GMP pathway. Thus, arginine treatment enhances signal transduction and has a beneficial effect of metabolism in skeletal muscle through direct activation of Akt and AMPK pathways. (C) 2013 Elsevier Inc. All rights reserved. (AU) | |