Plasma cytokine changes in relation to exercise intensity and muscle damage

Abstract

The purpose of this study was to compare the effects of exercise intensity and exercise-induced muscle damage on changes in anti-inflammatory cytokines and other inflammatory mediators. Nine well-trained male runners completed three different exercise trials on separate occasions: (1) level treadmill running at 60% VO2max (moderate-intensity trial) for 60 min; (2) level treadmill running at 85% VO2max (high-intensity trial) for 60 min; (3) downhill treadmill running (-10% gradient) at 60% VO2max (downhill running trial) for 45 min. Blood was sampled before, immediately after and 1 h after exercise. Plasma was analyzed for interleukin-1 receptor antagonist (IL-1ra), IL-4, IL-5, IL-10, IL-12p40, IL-13, monocyte chemotactic protein-1 (MCP-1), prostaglandin E(2), leukotriene B(4) and heat shock protein 70 (HSP70). The plasma concentrations of IL-1ra, IL-12p40, MCP-1 and HSP70 increased significantly (P<0.05) after all three trials. Plasma prostaglandin E(2) concentration increased significantly after the downhill running and high-intensity trials, while plasma IL-10 concentration increased significantly only after the high-intensity trial. IL-4 and leukotriene B(4) did not increase significantly after exercise. Plasma IL-1ra and IL-10 concentrations were significantly higher (P<0.05) after the high-intensity trial than after both the moderate-intensity and downhill running trials. Therefore, following exercise up to 1 h duration, exercise intensity appears to have a greater effect on anti-inflammatory cytokine production than exercise-induced muscle damage.

Repeated muscle damage blunts the increase in heat strain during subsequent exercise heat stress

“…It should be noted that in the study by Smith et al, cytokine concentrations were averaged over the 12 hour period following EIMD, thereby not providing useful information on the kinetics of the early inflammatory response immediately following EIMD (Smith et al 2007). We also assessed eHsp72 concentration, which has been shown to be elevated following downhill running (Peake et al 2005), and is also known to act as a "danger signal" activating the immune system (Horowitz and Robinson 2007;Whitham andFortes 2008) including IL-6 (Asea et al 2000). Furthermore, eHsp72 itself may have direct pyrogenic effects (Pastukhov et al 2003).…”

“…Blood samples were collected at pre-treatment, pre, post and 1-hour post HS on all trials and assessed for circulating inflammatory markers IL-6, IL-10, and heat shock protein (Hsp) 72 concentration. Circulating extracellular (e)Hsp72 was measured as concentrations have been shown to increase following EIMD (Peake et al 2005), eHsp72 itself may also have direct pyrogenic effects (Pastukhov et al 2003), and it provides an additional measure of the inflammatory response due to its immune-stimulating capability (Asea et al 2000;Whitham and Fortes 2008). Isometric leg strength of the quadriceps, and perceived muscle soreness were determined at baseline and 48-hours post trials to assess the degree of muscle damage.…”

Arterial stiffening following eccentric exercise-induced muscle damage

“…Eccentrically biased cycling or downhill running results in a greater increase in serum IL-1␤ and IL-6 than eccentric contractions (20,28,44,52) that is not explained by the magnitude of muscle damage. Because IL-6 is produced upon muscle contraction (14), dynamic eccentric-biased aerobic exercise will elicit greater hemodynamic changes that possibly contribute to increased "spillover" to the systemic circulation (42).…”

Efeito do exercício no sistema imune: resposta, adaptação e sinalização celular

“…Cytokines are low molecular weight (5,000 -30,000 Da) glycoproteins that play a central role in the mediation and regulation of immunological responses 12 . They act as messengers between the cells of the immune, hematopoietic and neuroendocrine systems 13 .…”