Moderate exercise triggers both priming and activation of
neutrophil subpopulations.
Smith, John A., A. Bon Gray, David B. Pyne, Mark S. Baker, Richard D.
Telford, and Maurice J. Weidemann.
Division of Biochemistry & Molecular Biology, School of Life
Sciences, Faculty of Science, Australian National University,
Canberra, ACT, 0200; Faculty of Nursing & Health Sciences,
Griffith University, PMB 50, Gold Coast Mail Centre, Qld, 4217;
Department of Physiology & Applied Nutrition, Australian Institute
of Sport, PO Box 176, Belconnen, ACT, 2616; and Department of
Biological Sciences, University of Wollongong, Wollongong, NSW, 2522,
Australia
APStracts 2:0289R, 1995.
We investigated how moderate exercise affects neutrophil microbicidal
activity and whether exercise-induced responses are associated with
changes in growth hormone (GH) secretion. Biological fluctuations
were controlled for and GH secretion was manipulated by glucose
ingestion. In eight men, one hour of moderate exercise increased
intracellular H2O2 generation in response to PMA stimulation by
three-fold (p = 0.025) and complement receptor expression by 20% (p =
0.045). These responses were accompanied by a two-fold increase in
the plasma concentration of elastase, a marker of neutrophil
activation in vivo. The plasma concentration of GH increased 10-fold
after exercise but this was reduced to three-fold by glucose
ingestion (p < 0.001) which also blunted elastase release (p
< 0.001). Although the magnitude of H2O2 generation increased in
proportion to the increase in plasma GH concentration, it declined
progressively once this exceeded 20 ng/ml. The net response of
neutrophils to exercise may represent a balance between the
individual responses of subpopulations that are unaffected, primed or
fully activated by circulating mediators that respond to exercise and
to dietary glucose intake.
Received 31 May 1995; accepted in final form 18 October 1995.
APS Manuscript Number R324-5.
Article publication pending Am. J. Physiol. (Regulatory Integrative
Comp. Physiology).
ISSN 1080-4757 Copyright 1995 The American Physiological Society.
Published in APStracts on 14 November 95