Effect of short-term exercise training on insulin-stimulated PI 3-kinase activity in middle-aged men.

Journal Article (Journal Article)

The purpose of this study was to determine whether the improved insulin action with short-term exercise training in middle-aged individuals is associated with enhanced phosphatidylinositol (PI) 3-kinase activity in skeletal muscle. Nine men of ages 50-70 yr were studied before and after 7 consecutive days of supervised exercise (60 min/day, 70% peak O2 consumption). Insulin sensitivity was measured with a euglycemic hyperinsulinemic glucose clamp in the sedentary condition and 15-17 h after the final exercise session. Anti-phosphotyrosine-associated PI 3-kinase activity was determined from muscle samples obtained in the fasted condition and after 60 min of insulin infusion during the clamp. With exercise, the glucose infusion rate increased (P < 0.001) by 33%, indicating enhanced insulin action (mean +/- SE, 6.6 +/- 0.6 vs. 8.7 +/- 0.8 mg x kg(-1) x min(-1)). Short-term exercise training did not, however, increase insulin-stimulated (insulin stimulated/fasting) PI 3-kinase activity (1.8 +/- 0.8 vs. 1.8 +/- 0.7-fold stimulation with insulin pre- vs. posttraining, respectively). There was also no change in insulin-stimulated protein kinase B activity (1.3 +/- 0.1 vs. 1.4 +/- 0.2-fold stimulation with insulin) with training. These data suggest that insulin action is enhanced with short-term exercise training via an adaptation distal to PI 3-kinase in middle-aged, insulin-resistant individuals.

Full Text

Duke Authors

Cited Authors

  • Tanner, CJ; Koves, TR; Cortright, RL; Pories, WJ; Kim, Y-B; Kahn, BB; Dohm, GL; Houmard, JA

Published Date

  • January 2002

Published In

Volume / Issue

  • 282 / 1

Start / End Page

  • E147 - E153

PubMed ID

  • 11739095

International Standard Serial Number (ISSN)

  • 0193-1849

Digital Object Identifier (DOI)

  • 10.1152/ajpendo.2002.282.1.E147


  • eng

Conference Location

  • United States