The Effect of Post-Resistance Exercise Amino Acids on Plasma MCP-1 and CCR2 Expression

Abstract

The recruitment and infiltration of classical monocytes into damaged muscle is critical for optimal tissue remodeling. This study examined the effects of an amino acid supplement on classical monocyte recruitment following an acute bout of lower body resistance exercise. Ten resistance-trained men (24.7 ± 3.4 years; 90.1 ± 11.3 kg; 176.0 ± 4.9 cm) ingested supplement (SUPP) or placebo (PL) immediately post-exercise in a randomized, cross-over design. Blood samples were obtained at baseline (BL), immediately (IP), 30-min (30P), 1-h (1H), 2-h (2H), and 5-h (5H) post-exercise to assess plasma concentrations of monocyte chemoattractant protein 1 (MCP-1), myoglobin, cortisol and insulin concentrations; and expressions of C-C chemokine receptor-2 (CCR2), and macrophage-1 antigen (CD11b) on classical monocytes. Magnitude-based inferences were used to provide inferences on the true effects of SUPP compared to PL. Changes in myoglobin, cortisol, and insulin concentrations were similar between treatments. Compared to PL, plasma MCP-1 was “very likely greater” (98.1% likelihood effect) in SUPP at 2H. CCR2 expression was “likely greater” at IP (84.9% likelihood effect), “likely greater” at 1H (87.7% likelihood effect), “very likely greater” at 2H (97.0% likelihood effect), and “likely greater” at 5H (90.1% likelihood effect) in SUPP, compared to PL. Ingestion of SUPP did not influence CD11b expression. Ingestion of an amino acid supplement immediately post-exercise appears to help maintain plasma MCP-1 concentrations and augment CCR2 expression in resistance trained men.

The Effects of Dietary Protein Supplementation on Exercise-Induced Inflammation and Oxidative Stress: A Systematic Review of Human Trials

“…Of the 34 included studies, 19 used a parallel group design [ 48 , 49 , 51 , 52 , 53 , 54 , 55 , 63 , 64 , 65 , 66 , 67 , 68 , 69 , 70 , 71 , 72 , 73 , 74 ], 3 had three treatment arms [ 52 , 54 , 63 ], and 2 had four treatment arms [ 68 , 74 ]. The remaining 15 studies employed a crossover design [ 8 , 30 , 50 , 56 , 75 , 76 , 77 , 78 , 79 , 80 , 81 , 82 , 83 , 84 , 85 ], three of which had three treatment arms [ 50 , 80 , 81 ].…”

“…The mean age of all the participants was 24 years, with an age range of 19–40 years. Nineteen studies recruited healthy athletes or highly trained professionals [ 8 , 30 , 48 , 50 , 55 , 56 , 65 , 70 , 71 , 74 , 76 , 77 , 78 , 79 , 80 , 82 , 83 , 84 , 85 ], and nine studies were conducted on recreationally active participants or participants that habitually performed resistance exercise training 1 to 2 days a week [ 51 , 53 , 54 , 66 , 67 , 69 , 72 , 73 , 81 ]. Six studies were on untrained participants [ 49 , 52 , 63 , 64 , 68 , 75 ].…”

“…By contrast, Rankin et al (2017) found that 500 mL of milk following eccentric exercise had no impact on the PC, high-sensitivity CRP (hsCRP) or reduced glutathione-to-oxidized glutathione ratio (GSH/GSSG). Similarly, three other studies found that milk-based beverages had no influence on several inflammatory markers post-exercise, including: TNF-α, tumor necrosis factor receptor 1 (TNFr1) expression on monocytes ( p > 0.05) [ 85 ], plasma monocyte chemoattractant protein 1 (MCP-1) ( p = 0.48), chemokine receptor type 2 (CCR2) expression (monocyte chemotaxis) ( p = 0.23), CD11 b expression (monocyte adhesion) ( p = 0.12), proportion of CD14+ relative to all leukocytes ( p = 0.27), CD14++CD16- monocytes relative to all monocytes ( p = 0.61) [ 84 ], IL-6, interleukin-1, and TNF-α ( p > 0.05) [ 52 ].…”

“…Five studies investigated the effect of combining different amino acids on biomarkers of oxidative stress and inflammation after exercise. One reported anti-inflammatory effects [ 68 ], one equivocal effect [ 73 ], and the remaining three showed no effect [ 65 , 72 , 84 ]. Ra et al [ 68 ] found that a combined taurine and BCAA supplement consumed for two weeks prior to and after eccentric elbow flexor exercise significantly lowered the serum levels of 8-hydroxydeoxyguanosine (8-OHdG), a marker of DNA damage, compared to the placebo and BCAA and placebo-only groups ( p < 0.05) but not compared to a taurine plus placebo group.…”

“…A limitation of many studies was insufficient statistical power. Seventeen studies out of thirty-four included less than twenty participants, and only 11 studies conducted a power analysis based on the published results to justify their sample sizes [ 8 , 51 , 54 , 70 , 73 , 76 , 78 , 79 , 80 , 84 , 85 ]. In one study [ 8 ], the desired sample size was not reached, and therefore, the statistical power may have been compromised.…”