Effects of Eccentric and Concentric Emphasized Resistance Exercise on IL-15 Serum Levels and Its Relation to Inflammatory Markers in Athletes and Non-Athletes

Abstract

Background:Cytokines play an important role in modulating the muscle’s metabolic and immunological responses to exercise.Objectives:In the present study, we investigated changes in the serum levels of Interleukin (IL)-15 as well as tumor necrosis factor (TNF)-α and high sensitivity C-reactive protein (hs-CRP), as markers of inflammation, in athlete and non-athlete young men following eccentric (ECC) and concentric (CON) emphasized resistance exercise (RE).Patients and Methods:This study recruited 28 young males, 14 athletes and 14 non-athletes. Subjects completed two bouts of ECC and CON emphasized RE five days apart. Each bout included seven exercises that emphasized all major muscle groups with weight loads of 70% - 80% of one repetition maximum (1RM) for CON RE and 90% - 100% of 1RM for ECC RE. We analyzed subjects’ blood samples before and immediately after each bout of exercise to determine cytokine and hs-CRP serum levels according to enzyme-linked immunosorbent assay.Results:Statistical analysis showed a significant difference between IL-15 serum levels before and after ECC and CON RE in non-athletes (P = 0.03). In athletes, IL-15 serum level only increased after ECC RE (P = 0.01), which was noted to be the highest degree of change in IL-15 levels in all subjects. For athletes, the hs-CRP levels significantly decreased (P < 0.05). The serum levels of both TNF-α and hs-CRP were also significantly down-regulated after ECC RE in non-athletes.Conclusions:These results indicated that fitness level and RE could modulate circulating levels of IL-15 and suggest the potential anti-inflammatory effects of IL-15 during RE.

Exercise effects on perivascular adipose tissue: endocrine and paracrine determinants of vascular function

“…Although IL‐15 is considered a pro‐inflammatory cytokine, the fact that its circulating levels are negatively related to obesity, WAT mass and type 2 diabetes is also consistent with a role as a myokine (Quinn et al ., ). Moreover, both endurance training in Zucker rats (Kim et al ., ) and RT in controls and athletes increased circulating IL‐15 levels (Bazgir et al ., ). In both cases, exercise was negatively related to body fat and inflammatory markers.…”

Acute long-distance trail running increases serum IL-6, IL-15, and Hsp72 levels

“…Administration of IL-15 has been shown to reduce the volume of white adipose tissue in animal experiments (Carbó et al 2001). In humans, when IL-15 is perfused on adipose tissue by a microdialysis probe, this effect is observed in the lean subjects but not in the obese (Pierce et al 2015 (Bazgir et al 2015b). The IL-15 response to ultra-endurance activities has not yet been investigated.…”

“…Although it is known that IL-6, IL-15 and Hsp72 levels increase following exercise, there are contradictory results concerning whether this increase can be found after any exercise bout in any population and the magnitude of the increase. For instance, IL-15 elevation is found to be prominent following concentric and eccentric exercise in sedentary people, but only eccentric exercise elevated serum IL-15 levels in athletes (Bazgir et al 2015a). The most prominent increase in the prototype myokine IL-6 is observed after running exercise involving several large muscle groups (Febbraio and Pedersen 2002).…”

Metabolic Health—The Role of Adipo-Myokines

“…The serum level of TNF-α was significantly downregulated after eccentric resistance exercise in non-athletes [54].…”

“…discussed: Strength/resistance training leads to an increase in IL-15 messenger RNA (mRNA) level in skeletal muscles dominated by type 2 fibers[53,54]. Short bout of endurance exercise also increases levels of IL-15 in lean subjects, as well as in overweight/obese, subjects[55].…”