In humans IL-6 is released from the brain during and after exercise and paralleled by enhanced IL-6 mRNA expression in the hippocampus of mice

TY - JOUR

T1 - In humans IL-6 is released from the brain during and after exercise and paralleled by enhanced IL-6 mRNA expression in the hippocampus of mice

AU - Rasmussen, Per

AU - Vedel, J-C

AU - Olesen, J

AU - Adser, Helle

AU - Pedersen, M V

AU - Hart, E

AU - Secher, N H

AU - Pilegaard, H

N1 - © 2010 The Authors. Acta Physiologica © 2010 Scandinavian Physiological Society.

PY - 2011/4

Y1 - 2011/4

N2 - Aim: Plasma interleukin-6 (IL-6) increases during exercise by release from active muscles and during prolonged exercise also from the brain. The IL-6 release from muscles continues into recovery and we tested whether the brain also releases IL-6 in recovery from prolonged exercise in humans. Additionally, it was evaluated in mice whether brain release of IL-6 reflected enhanced IL-6 mRNA expression in the brain as modulated by brain glycogen levels. Methods: Nine healthy male subjects completed 4h of ergometer rowing while the arterio-jugular venous difference (a-v diff) for IL-6 was determined. The IL-6 mRNA and the glycogen content were determined in mouse hippocampus, cerebellum and cortex before and after 2h treadmill running (N=8). Results: At rest, the IL-6 a-v diff was negligible but decreased to -2.2±1.9pgml-1 at the end of exercise and remained low (-2.1± 2.1pgml-1) 1h into the recovery (P<0.05 vs. rest). IL-6 mRNA was expressed in the three parts of the brain with the lowest content in the hippocampus (P<0.05) coupled to the highest glycogen content (3.2±0.8mmolkg-1). Treadmill running increased the hippocampal IL-6 mRNA content 2-3-fold (P<0.05), while the hippocampal glycogen content decreased to 2.6±0.6mmolkg-1 (P<0.05) with no significant changes in the two other parts of the brain. Conclusion: Human brain releases IL-6 both during and in recovery from prolonged exercise and mouse data suggest that concurrent changes in IL-6 mRNA and glycogen levels make the hippocampus a likely source of the IL-6 release from the brain.

AB - Aim: Plasma interleukin-6 (IL-6) increases during exercise by release from active muscles and during prolonged exercise also from the brain. The IL-6 release from muscles continues into recovery and we tested whether the brain also releases IL-6 in recovery from prolonged exercise in humans. Additionally, it was evaluated in mice whether brain release of IL-6 reflected enhanced IL-6 mRNA expression in the brain as modulated by brain glycogen levels. Methods: Nine healthy male subjects completed 4h of ergometer rowing while the arterio-jugular venous difference (a-v diff) for IL-6 was determined. The IL-6 mRNA and the glycogen content were determined in mouse hippocampus, cerebellum and cortex before and after 2h treadmill running (N=8). Results: At rest, the IL-6 a-v diff was negligible but decreased to -2.2±1.9pgml-1 at the end of exercise and remained low (-2.1± 2.1pgml-1) 1h into the recovery (P<0.05 vs. rest). IL-6 mRNA was expressed in the three parts of the brain with the lowest content in the hippocampus (P<0.05) coupled to the highest glycogen content (3.2±0.8mmolkg-1). Treadmill running increased the hippocampal IL-6 mRNA content 2-3-fold (P<0.05), while the hippocampal glycogen content decreased to 2.6±0.6mmolkg-1 (P<0.05) with no significant changes in the two other parts of the brain. Conclusion: Human brain releases IL-6 both during and in recovery from prolonged exercise and mouse data suggest that concurrent changes in IL-6 mRNA and glycogen levels make the hippocampus a likely source of the IL-6 release from the brain.

U2 - 10.1111/j.1748-1716.2010.02223.x

DO - 10.1111/j.1748-1716.2010.02223.x

M3 - Journal article

C2 - 21083649

SN - 1748-1708

VL - 201

SP - 475

EP - 482

JO - Acta Physiologica (Print)

JF - Acta Physiologica (Print)

IS - 4

ER -