Relationships Of Serum And Plasma BDNF To TNF-a, IL-10, And IL-1ra During Aerobic Exercise

Abstract

PURPOSE: To examine the relationship of Brain Derived Neurotrophic Factor (BDNF) in serum and plasma to serum TNF-α, IL-10, and IL-1ra in response to aerobic exercise. METHODS: Six recreationally active men (26.0 ± 2.6 yrs, 180.3 ± 5.3 cm, 85.3 ± 7.6 kg, 48.64 ± 5.2 mL·kg-1·min-1) completed three exercise trials under different conditions: low temperature (5°C), moderate temperature (22°C), and high temperature (35°C). Each protocol consisted of a 60-min cycling trial at 60% VO2max, a 15-min rest, and a time-to-exhaustion trial at 90% VO2max (TTE). Blood was sampled before (PRE) and after the 60-min time trial (60), immediately following the TTE (90), and one hr post-TTE (REC). Serum concentrations of TNF-α, IL-10, IL-1ra, BDNF(-S), and plasma concentrations of BDNF(-P) were analyzed via ELISA. Data were combined across different conditions and analyzed by calculating change scores between PRE and other time points – presented as 60, 90, REC. Relationships between analytes were determined using Pearson Product Moment Correlations, with α ≤ 0.05. Correlation coefficients were described as weak (r: 0.30 – 0.49), moderate (r: 0.50 – 0.69), or strong (r: 0.70 – 0.89). RESULTS: Correlation coefficients between changes in BDNF-S and changes in IL-1ra indicated moderate to strong positive relationships between BDNF-S at 60 with IL-1ra at 60 and 90, BDNF-S at 90 with IL-1ra at 90, and BDNF-S at REC with IL-1ra at 90 and REC (r ≥ 0.568, p ≤ 0.043). Correlation coefficients between BDNF-P and TNF-α indicated a moderate positive relationship between BDNF-P at 60 with TNF-α at 90 (r = 0.513, p = 0.035). Changes in BDNF-S and IL-1ra demonstrated weak to moderate, non-significant correlation coefficients between BDNF-S at 90 and REC with IL-1ra at 60 (r = 0.456, p = 0.087; r = 0.508, p = 0.064; respectively). Similarly, correlation coefficients between changes in BDNF-S and IL-10 presented weak to moderate, non-significant relationships BDNF at 60 and 90 with IL-10 at 60 (r = 0.544, p = 0.068; r = 0.498, p = 0.070; respectively). No other relationships were observed. CONCLUSION: There appears to be a strong relationship between BDNF-S and IL-1ra throughout the trial, suggesting BDNF may be linked to the anti-inflammatory cascade, though not corroborated in BDNF-P.