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Glucose production during strenuous exercise in humans : role of epinephrine

journal contribution
posted on 1999-06-01, 00:00 authored by Kirsten HowlettKirsten Howlett, M Febbraio, Mark Hargreaves
The increase in hepatic glucose production (HGP) that occurs during intense exercise is accompanied by a simultaneous increase in epinephrine, which suggests that epinephrine may be important in regulating HGP. To further investigate this, six trained men were studied twice. The first trial [control (Con)] consisted of 20 min of cycling at 40 ± 1% peak oxygen uptake (V˙o 2 peak) followed by 20 min at 80 ± 2%V˙o 2 peak. During the second trial [epinephrine (Epi)], subjects exercised for 40 min at 41 ± 2%V˙o 2 peak. Epinephrine was infused during the latter 20 min of exercise and resulted in plasma levels similar to those measured during intense exercise in Con. Glucose kinetics were measured using a primed, continuous infusion of [3-3H]glucose. HGP was similar at rest (Con, 11.0 ± 0.5 and Epi, 11.1 ± 0.5 μmol ⋅ kg−1 ⋅ min−1). In Con, HGP increased (P < 0.05) during exercise to 41.0 ± 5.2 μmol ⋅ kg−1 ⋅ min−1at 40 min. In Epi, HGP was similar to Con during the first 20 min of exercise. Epinephrine infusion increased (P < 0.05) HGP to 24.0 ± 2.5 μmol ⋅ kg−1 ⋅ min−1at 40 min, although this was less (P< 0.05) than the value in Con. The results suggest that epinephrine can increase HGP during exercise in trained men; however, epinephrine during intense exercise cannot fully account for the rise in HGP. Other glucoregulatory factors must contribute to the increase in HGP during intense exercise.

History

Journal

American journal of physiology

Volume

276

Issue

6

Publisher

American Physiological Society

Location

Bethesda, Md.

ISSN

0193-1849

eISSN

1522-1555

Language

eng

Publication classification

C1.1 Refereed article in a scholarly journal

Copyright notice

1999, American Physiological Society