Title

Gender differences in endocrine-immune interactions in response to acute resistance exercise

Date of Completion

January 2009

Keywords

Health Sciences, Recreation|Biology, Physiology

Degree

Ph.D.

Abstract

The immune and neuro-endocrine systems are closely integrated by sharing both common peptide hormones and receptors. This endocrine-immune communication in response to exercise is not clearly understood. The purpose of this investigation was to examine potential gender differences in endocrine-immune interactions in response to an acute bout of resistance exercise. Seven physically active and resistance trained women (mean ± SD age: 22.13 ± 3.09 y; height: 1.69 ± 0.084 m; body mass: 65.60 ± 10.01 kg; body mass index: 22.63 ± 2.03 kg/m2) and eight physically active and resistance trained men (mean ± SD age: 23.28 ± 4.26 y; height: 1.73 ± 0.086 m; body mass: 73.93 ± 12.71 kg; body mass index: 24.51 ± 2.61 kg/m2) performed an acute resistance exercise protocol (6 sets of 5 repetitions of squats) and a control test (sitting quietly under identical conditions) in a randomized order. Glucocorticoid (GCR), β2-Adrenergic (β2-ADR), and Estradiol β (ER) receptors on circulating leukocytes were evaluated with flow cytometry. Circulating hormones (cortisol, epinephrine, norepinephrine) were assayed. Resting GCR and β2-ADR expression on leukocytes were similar between resistance trained, healthy men and women. On monocyte and granulocyte sub-populations, GCR expressions were elevated in anticipation of the exercise protocol, decreased during the exercise and increased during recovery. Also, on monocytes, β2-ADR expressions were elevated in anticipation of the exercise protocol and then decreased. Lymphocytes tended to have elevated GCR and β2-ADR expression during the recovery time points. Gender differences were observed in β2-ADR expression on overall leukocytes at 1-hr post exercise, in circulating cortisol responses to the exercise protocol, and circulating creatine kinase responses during the recovery period. ER on leukocyte subpopulations showed no gender differences or changes in response to the exercise protocol. In conclusion, GCR and β2-ADR expression on leukocyte subpopulations responded to acute heavy resistance exercise, and gender differences were apparent in endocrine-immune interactions in response to exercise; however, they are unlikely explained by ER receptors on leukocytes. ^