Chronic exercise decreases cytokine production in healthy rat skeletal muscle

Abstract

Skeletal muscle is the source of pro- and anti-inflammatory cytokines, and recently, it has been recognized as an important source of interleukin-6 (IL-6). Acute physical exercise is known to induce a pro-inflammatory cytokine profile in the plasma. However, the effect of chronic physical exercise in the production of pro- and anti-inflammatory cytokines by the skeletal muscle has never been examined. We assessed IL-6, TNF-alpha, IL-1beta and IL-10 levels in the skeletal muscle of rats submitted to endurance training. Animals were randomly assigned to either a sedentary group (S, n = 7) or an endurance exercise trained group (T, n = 8). Trained rats ran on a treadmill for 5 days week(-1) for 8 weeks (60% VO(2max)). Detection of IL-6, TNF-alpha, IL-1beta and IL-10 protein expression was carried out by ELISA. We found decreased expression of IL-1beta, IL-6, TNF-alpha and IL-10 (28%, 27%, 32% and 37%, respectively, p < 0.05) in the extensor digital longus (EDL) from T, when compared with S. In the soleus, IL-1beta, TNF-alpha and IL-10 protein levels were similarly decreased (34%, 42% and 50%, respectively, p < 0.05) in T in relation to S, while IL-6 expression was not affected by the training protocol. In conclusion, exercise training induced decreased cytokine protein expression in the skeletal muscle. These data show that in healthy rats, 8-week moderate-intensity aerobic training down regulates skeletal muscle production of cytokines involved in the onset, maintenance and regulation of inflammation, and that the response is heterogeneous according to fibre composition.

Chronic low frequency/low volume resistance training reduces pro-inflammatory cytokine protein levels and TLR4 mRNA in rat skeletal muscle

“…Regular physical activity, especially aerobic exercise, has been shown to decrease the production of pro-inXammatory cytokines in plasma and tissues (Pedersen and Saltin 2006;Lira et al 2009a;Rosa Neto et al 2009). Such eVect has been considered dependent of contractile muscle activity through interleukin-6 production (Steensberg et al 2000), a cytokine that exerts inhibitory eVects on several pro-inXammatory cytokines, among them TNF- (Mathur and Pedersen 2008).…”

Effect of resistance exercise training on expression of Hsp70 and inflammatory cytokines in skeletal muscle and adipose tissue of STZ-induced diabetic rats

“…Hypertrophy of skeletal muscle and the resulting concomitant gain in power are of great interest for people with disease-induced atrophy such as type 1 diabetes. It has been suggested that aerobic exercise training can change the expression of stress and inflammatory factors in different tissues (Rosa Neto et al 2009;Lira et al 2009). On the other hand, some studies proposed that resistance training did not reduce inflammatory and stress factors in individuals with metabolic risk factors (Levinger et al 2009;Calle and Fernandez.…”

Exercise training in chronic heart failure: improving skeletal muscle O2transport and utilization

“…Enhanced cytokine levels have been implicated in 1) endothelial dysfunction via increased ROS production (54); 2) increased expression of adhesion molecules (232); 3) endothelial cell apoptosis (263); 4) impairments in skeletal muscle oxidative metabolism (6,110,117); and 5) impairments in submaximal exercise Q m (283). Training-induced reductions in the expression of inflammatory mediators such as TNF-␣, IL-6, IL-1-␤, and inducible NOS (3,4,57,93,94,189,190,195) and increases of the anti-inflammatory mediator IL-10 (24, 25, 233) may be of significant benefit in CHF and relevant to muscle Q mO 2 -to-V mO 2 matching during exercise.…”