Acute Psychosocial Stress Induces Changes in Norepinephrine Sensitivity of Stimulated TNF-Alpha Production

Karen Kaye

doi:10.48617/etd.773

Background and Rationale: It is well established that psychosocial stress induces changes in glucocorticoid (GC) sensitivity, but little is known about how repeated psychosocial stress induces changes in norepinephrine sensitivity of stimulated TNF-α production. Psychosocial stress induces an increase in blood concentrations of catecholamines, which are important modulators of the immune system. Since stress is known to exacerbate the symptoms of autoimmune disorders, which disproportionally affect women, and catecholamine resistance has been reported among women with autoimmune disorders, it is important to study inflammatory cytokine sensitivity catecholamine differences in both men and women. Little is also known about how catecholamine responses to stress and catecholamine sensitivity of immune cells changes with increasing age. Thus, the current study set out to assess gender and age differences in alterations of in vitro sensitivity of inflammatory cytokine production to the effects of norepinephrine.\r Methods: Thirty-five younger (18-35) and older (50-64) males (N=12) and females (23) were subjected to the Trier Social Stress Test (TSST) on two consecutive days, and salivary alpha-amylase responses and catecholamine sensitivity were measured. Enzyme-linked immunosorbent assay (ELISA) kits were used to analyze concentrations of the pro-inflammatory cytokine Tumor Necrosis Factor α (TNF- α), and colorimetric assays were used to analyze alpha amylase concentrations. \r Results: Men and women significantly differed in sensitivity on day 1 (time*gender effect: F4, 148= 3.464, p< .01), where females showed a decrease in sensitivity and males show increased sensitivity. However, gender differences were not found on day 2 (time*gender effect: F4, 176= 1.636, p< .167), where men and women both showed decreases in catecholamine sensitivity. Older (50-64 years) and younger (18-35 years) groups did not significantly differ in catecholamine sensitivity overall (F5,165= 0.670, p= .647). Figure 3 and Table 1 could not be embedded within the file. \r Conclusions: To the best of our knowledge, this is the first report of showing gender differences with inflammatory cytokine production to the immunosuppressive effects of catecholamines after repeated stress. Future studies on stress effects on inflammatory regulation will have to include assessments of both, glucocorticoid and catecholamine sensitivity in addition to measurements of circulating hormone levels.

Acute Psychosocial Stress Induces Changes in Norepinephrine Sensitivity of Stimulated TNF-Alpha Production

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