Insulin-stimulated insulin recetor substrate-2-associated phosphatidylinositol 3-kinase activity is enhanced in human skeletal muscle after exercise.
Data(s) |
01/08/2006
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Resumo |
Exercise increases skeletal muscle insulin action but the underlying mechanisms mediating this are equivocal. In mouse skeletal muscle, prior exercise enhances insulin-stimulated insulin receptor substrate-2 (IRS-2) signaling (<i>Diabetes</i> 2002;51:479-83), but it is unknown if this also occurs in humans. Hyperinsulinemic-euglycemic clamps were performed on 7 untrained males at rest and immediately after 60 minutes of cycling exercise at ~75% Vo<sub>2peak</sub>. Muscle biopsies were obtained at basal, immediately after exercise, and at 30 and 120 minutes of hyperinsulinemia. Insulin infusion increased (P < .05) insulin receptor tyrosine phosphorylation similarly in both the rest and exercise trials. Under resting conditions, insulin infusion resulted in a small, but non–statistically significant increase in IRS-2–associated phosphatidylinositol 3 (PI 3)–kinase activity over basal levels. Exercise per se decreased (P < .05) IRS-2–associated PI 3–kinase activity. After exercise, insulin-stimulated IRS-2–associated PI 3–kinase activity tended to increase at 30 minutes and further increased (P < .05) at 120 minutes when compared with the resting trial. Insulin increased (P < .05) Akt Ser<sup>473</sup> and GSK-3α/β Ser<sup>21</sup>/Ser<sup>9</sup> phosphorylation in both trials, with the response tending to be higher in the exercise trial. In conclusion, in the immediate period after an acute bout of exercise, insulin-stimulated IRS-2 signaling is enhanced in human skeletal muscle.<br /><br /><br /> |
Identificador | |
Idioma(s) |
eng |
Publicador |
Elsevier Inc |
Relação |
http://dro.deakin.edu.au/eserv/DU:30003566/n20060293.pdf http://dx.doi.org/10.1016/j.metabol.2006.03.016 |
Direitos |
2006, Elsevier Inc. |
Tipo |
Journal Article |