Effect of running intensity on intestinal permeability.
Pals, Kay L., Ray-Tai Chang, Alan J. Ryan, and Carl V. Gisolfi.
Department of Exercise Science, N414 Field House, University of
Iowa, Iowa City, IA 52242-1111
APStracts 3:0485A, 1996.
Enhanced intestinal permeability has been associated with
gastrointestinal disorders in long distance runners. The primary
purpose of this study was to evaluate the effect of running intensity
on small intestinal permeability using the lactulose and rhamnose
differential urinary excretion test. Secondary purposes included
assessing the relationship between small intestinal permeability and
gastrointestinal symptoms and evaluating gastric damage utilizing
sucrose as a probe. Six healthy volunteers (5 males, 1 female; age =
30 2 yrs; peak VO2 = 57.7 2.1 mL[tilde]nKg-1[tilde]nmin-1) rested or
performed treadmill exercise at 40%, 60% or 80% peak VO2 for 60 min
in a moderate environment (22[acute]iC, 50% rh). 30 min into rest or
exercise the permeability test solution (5 g sucrose, 5 g lactulose,
2 g rhamnose in 50 mL water; 800 mOsm[tilde]nL-1) was ingested.
Urinary excretion rates (6 h) of the lactulose/rhamnose ratio were
used to assess small intestinal permeability and concentrations of
each probe were determined using high pressure liquid chromatography.
Running at 80% peak VO2 increased (p < 0.05) small intestinal
permeability compared with rest, 40%, and 60% peak VO2 with mean
values ( SE) expressed as percent recovery of ingested dose of 0.107
0.021%, 0.048 0.009%, 0.056 0.005%, and 0.064 0.010%, respectively.
Increases in small intestinal permeability did not result in a higher
prevalence of gastrointestinal symptoms and urinary recovery of
sucrose did not reflect increased gastric permeability. The
significance and mechanisms involved in increased small intestinal
permeability following high intensity running merit further
investigation.
Received 22 May 1996; accepted in final form 16 October 1996.
APS Manuscript Number A487-6.
Article publication pending Journal of Applied Physiology.
ISSN 1080-4757 Copyright 1996 The American Physiological Society.
Published in APStracts on 13 November 1996