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Increased insulin-stimulated Akt pSer473 and cytosolic SHP2 protein abundance in human skeletal muscle following acute exercise and short-term training.

journal contribution
posted on 2007-01-01, 00:00 authored by Glenn WadleyGlenn Wadley, Nicky Konstantopoulos, L Macaulay, Kirsten HowlettKirsten Howlett, Andrew GarnhamAndrew Garnham, Mark Hargreaves, David Cameron-Smith
The purpose of the present study was to determine in human skeletal muscle whether a single exercise bout and 7 days of consecutive endurance (cycling) training 1) increased insulin-stimulated Akt pSer473and 2) altered the abundance of the protein tyrosine phosphatases (PTPases), PTP1B and SHP2. In healthy, untrained men (n = 8; 24 ± 1 yr), glucose infusion rate during a hyperinsulinemic euglycemic clamp, when compared with untrained values, was not improved 24 h following a single 60-min bout of endurance cycling but was significantly increased (~30%; P < 0.05) 24 h following completion of 7 days of exercise training. Insulin-stimulated Akt pSer473was ~50% higher (P < 0.05) 24 h following the acute bout of exercise, with this effect remaining after 7 days of training (P < 0.05). Insulin-stimulated insulin receptor and insulin receptor substrate-1 tyrosine phosphorylation were not altered 24 h after acute exercise and short-term training. Insulin did not acutely regulate the localization of the PTPases, PTP1B or SHP2, although cytosolic protein abundance of SHP2 was increased (P < 0.05; main effect) 24 h following acute exercise and short-term training. In conclusion, insulin-sensitive Akt pSer473and cytosolic SHP2 protein abundance are higher after acute exercise and short-term training, and this effect appears largely due to the residual effects of the last bout of prior exercise. The significance of exercise-induced alterations in cytosolic SHP2 and insulin-stimulated Akt pSer473on the improvement in insulin sensitivity requires further elucidation.

History

Journal

Journal of applied physiology

Volume

102

Issue

4

Pagination

1624 - 1631

Publisher

American Physiological Society

Location

Washington, D.C.

ISSN

8750-7587

eISSN

1522-1601

Language

eng

Publication classification

C1.1 Refereed article in a scholarly journal

Copyright notice

2007, American Physiological Society