Endotoxaemia, production of tumour necrosis factor ? and polymorphonuclear neutrophil activation following strenuous exercise in humans

Abstract

To examine whether endotoxaemia accompanying long-term, strenuous physical exercise is involved in exercise-induced increase in plasma tumour necrosis factor alpha (TNF-alpha) concentration and polymorphonuclear neutrophil (PMN) activation, 14 male recreational athletes [mean age 28 (SEM 1) years] were studied. Exercise consisted of a 1.5-km river swim, a 40-km bicycle race, and a 10-km road race. Mean time to complete the race was 149.8 (SEM 4.8) min. The plasma concentrations of granulocyte myeloperoxidase (MPO) and TNF-alpha were significantly higher than baseline values immediately and 1 h after exercise (P<0.001). Both variables returned to pre-race levels the day after exercise. Marked, transient decreases in plasma concentrations of anti-lipopolysaccharide (LPS) immunoglobulin G (IgG) and immunoglobulin M (IgM) antibodies directed against a panel of selected smooth gram-negative LPS were observed after the race, reaching in most cases minimal values in the blood sample drawn immediately following the completion of the triathlon. There was no significant correlation between the magnitude of PMN activation, as assessed by the increase in plasma concentrations of MPO, and the humoral markers of endotoxaemia and TNF-alpha. An inverse, highly significant relationship between the increase in plasma TNF-alpha concentrations and the changes in circulating anti-LPS IgM antibodies concentrations was observed (r = -0.7; P<0.01). These findings suggest that exercise-induced endotoxaemia was involved in the release of TNF-alpha, that the magnitude of the TNF-alpha response to exercise was down-regulated by anti-LPS antibodies of the IgM class, and that the production of TNF-alpha and endotoxaemia did not seem to play a role in the activation of circulating PMN in the exercising subjects.

Acute hepatic response to diet modification and exercise-induced endotoxemia during a laboratory-based duathlon

“…This exercise intensity caused bacterial translocation immediately following exercise similar to that reported in marathon and ultra-endurance events [3,4,6,7,27,44].…”

“…Based on the IL-6 response to exercise from previous studies [6,14], and using the nQuery Advisor® statistical sample size software, it was estimated that a sample size of 10 would have a power (β =0.80) to detect an effect size of 0.996 with a 0.05 significance level [43].…”

The Gastrointestinal Circulation: Physiology and Pathophysiology

“…Studies of intestinal ischemia in experimental animals have revealed that a reduction of blood flow of this magnitude and duration would likely result in a profound increase in mucosal permeability to macromolecules as well as bacterial translocation (82,365,429). Such a loss of mucosal integrity and barrier function is likely reflected in the increased levels of intestinal fatty acid-binding protein (I-FABP) and endotoxin detected in the plasma of young healthy athletes during strenuous exercise (17,55,67,218,520). Mucosal barrier disruption has been confirmed in young athletes, based on urinary clearance of orally ingested permeability probes, as early as 1 h after strenuous exercise (300,501).…”

Exhaustive exercise causes an anti-inflammatory effect in skeletal muscle and a pro-inflammatory effect in adipose tissue in rats

“…Therefore, a single bout of exercise is a mild physical stressor that exerts an array of eVects on immune parameters (Sprenger et al 1992;Schulz et al 2004). The body reacts to physical activity as it does during an acute, subclinical inXammatory response to a perceived pathological insult (Bury et al 1996;Camus et al 1998).…”