B2-Adrenergic Receptor Expression on Human Leukocytes in Response to Acute Heavy Resistance Exercise

Abstract

Epinephrine and norepinephrine mediate interactions between the neuro-endocrine and the immune systems, to alter immune cell activity. While both systems respond to exercise stress, less in known about how they interact in response to such stress. PURPOSE: To examine B2-Adrenergic receptor (B2-ADR) expression on circulating leukocytes to an acute bout of resistance exercise in men and women. METHODS: Resistance trained men (mean ± SD (n=8) age: 23.28 ± 4.26 y; body mass index: 24.51 ± 2.61 kg/m2) and women ((n=7) age: 22.13 ± 3.09 y; body mass index: 22.63 ± 2.03 kg/m2) performed an acute resistance exercise protocol (6 sets of 5 RM heavy squats) and a control test (i.e., identical conditions with no exercise) in a balanced, randomized order. Using a within subject design, B2-Adrenergic receptor (B2-ADR) expression on circulating leukocytes were evaluated with flow cytometry and plasma epinephrine and norepinephrine were evaluated with high performance liquid chromatography. RESULTS: Plasma epinephrine and norepinephrine increased during the exercise bout and returned to baseline during recovery (p<0.05). B2-ADR expression on monocytes was elevated in anticipation of the exercise protocol (p<0.05). B2-ADR expression on monocytes and granulocytes decreased during the exercise (p<0.05). B2-ADR expression on lymphocytes was elevated during the recovery time points (p<0.05). CONCLUSION: B2-ADR expression on leukocyte subpopulations changes in response to acute heavy resistance exercise protocol. Present findings provide insights into the temporal interactions between the neuro-endocrine and the immune systems in response to the physiological stress of acute heavy resistance exercise in men and women.