Mediators of monocyte migration in response to recovery modalities following resistance exercise

Abstract

Mediators of monocyte migration, complement receptor-3 (CR3), and chemokine ligand-4 (CCL4) were measured in response to recovery modalities following resistance exercise. Thirty resistance-trained men (23.1 ± 2.9 y; 175.2 ± 7.1 cm; 82.1 ± 8.4 kg) were given neuromuscular electric stimulation (NMES), cold water immersion (CWI), or control (CON) treatments immediately following resistance exercise. Blood samples were obtained preexercise (PRE), immediately (IP), 30 minutes (30 P), 24 hours (24 H), and 48 hours (48 H) after exercise for measurement of circulating CCL4 and CR3 expression on CD14+ monocytes, by assay and flow cytometry. Circulating CCL4 showed no consistent changes. Inferential analysis indicated that CR3 expression was likely greater in CON at 30 P than NMES (90.0%) or CWI (86.8%). NMES was likely lower than CON at 24 H (92.9%) and very likely lower at 48 H (98.7%). Expression of CR3 following CWI was very likely greater than CON (96.5%) at 24 H. The proportion of CR3+ monocytes was likely greater following CWI than NMES (85.8%) or CON (85.2%) at 24 H. The change in proportion of CR3+ monocytes was likely (86.4%) greater following NMES than CON from IP to 30 P. The increased expression of CR3 and increased proportion of CR3+ monocytes following CWI at 24 H indicate a potentially improved ability for monocyte adhesion to the endothelium, possibly improving phagocytosis of damaged tissues.

Figure 1

Gating procedures for CD14+ cells. (a) CD14+ cells selected from the specified region based on forward (FSC) and side scatter (SSC) properties. (b) Two-dimensional histogram displaying fluorescence characteristics of cells in selected region. Cells positive for CR3 and CD14 are displayed in the upper right quadrant.

Figure 2

Circulating Concentration of CCL4 (mean ± SE). Changes in CCL4 concentration before exercise (PRE), immediately after exercise (IP), and 30 minutes (30 P), 24 hours (24 H), and 48 hours (48 H) after exercise in neuromuscular electrical stimulation (NMES), cold water immersion (CWI), and control (CON) groups. (a) The value is “likely” greater than CON at the specified time point. (b) The value is “possibly” greater than CON at the specified time point.

Figure 3

Expression of the complement receptor 3 (CR3) on CD14+ monocytes (mean ± SE). CR3 expression, as measured by mean fluorescence intensity before exercise (PRE), immediately after exercise (IP), and 30 minutes (30 P), 24 hours (24 H), and 48 hours (48 H) after exercise in neuromuscular electrical stimulation (NMES), cold water immersion (CWI), and control (CON) groups. (a) The value is “likely” lower than CON at the specified time point, (b) the value is “very likely” lower than CON at the specified time point, and (c) the value is “very likely” lower than CWI at the specified time point.

Figure 4

Proportion of CR3+/CD14+ monocytes (mean ± SE). Changes in CR3 expression before exercise (PRE), immediately after exercise (IP), and 30 minutes (30 P), 24 hours (24 H), and 48 hours (48 H) after exercise in neuromuscular electrical stimulation (NMES), cold water immersion (CWI), and control (CON) groups. (a) A “likely” lower value than CWI at the specified time point. (b) A “likely” greater change from IP than CON at the specified time point.