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L-Arginine infusion increases glucose clearance during prolonged exercise in humans

journal contribution
posted on 2006-01-01, 00:00 authored by G McConell, N Huynh, R Lee-Young, B Canny, Glenn WadleyGlenn Wadley
Nitric oxide synthase (NOS) inhibition has been shown in humans to attenuate exercise-induced increases in muscle glucose uptake. We examined the effect of infusing the NO precursor L-arginine (L-Arg) on glucose kinetics during exercise in humans. Nine endurance-trained males cycled for 120 min at 72 ± 1% VO2 peak followed immediately by a 15-min "all-out" cycling performance bout. A [6,6-2H]glucose tracer was infused throughout exercise, and either saline alone (Control, CON) or saline containing L-Arg HCl (L-Arg, 30 g at 0.5 g/min) was coinfused in a double-blind, randomized order during the last 60 min of exercise. L-Arg augmented the increases in glucose rate of appearance, glucose rate of disappearance, and glucose clearance rate (L-Arg: 16.1 ± 1.8 ml·min–1·kg–1; CON: 11.9 ± 0.7 ml·min–1·kg–1 at 120 min, P < 0.05) during exercise, with a net effect of reducing plasma glucose concentration during exercise. L-Arg infusion had no significant effect on plasma insulin concentration but attenuated the increase in nonesterified fatty acid and glycerol concentrations during exercise. L-Arg infusion had no effect on cycling exercise performance. In conclusion, L-Arg infusion during exercise significantly increases skeletal muscle glucose clearance in humans. Because plasma insulin concentration was unaffected by L-Arg infusion, greater NO production may have been responsible for this effect.

History

Journal

American journal of physiology : endocrinology and metabolism

Volume

290

Issue

1

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

2006, American Physiological Society