Chronic Stress Induces Persistent Low-Grade Inflammation

Abstract Introduction This study sought to determine if the systemic cytokine profile of rodents subjected to chronic restraint stress leads to persistent low-grade inflammation. Methods Male Sprague-Dawley rats were subjected to restraint stress for a total of seven or fourteen days. Urine norepinephrine (NE), plasma interleukin 6 (IL-6), tumor necrosis factor alpha (TNF-α), C-reactive protein (CRP) were assessed with ELISA. Liver expression of IL-6 and TNF-α were assessed with real time PCR. Results Chronic stress at 7 and 14 days sequentially increased plasma acute phase reactants (NE, IL-6, TNF-α, and CRP), liver IL-6 expression, hematopoietic progenitor cell mobilization, and decreased erythroid progenitor colony growth. Weight gain was reduced by chronic stress compared to each models’ naive counterpart. Conclusions Combining this model with trauma and sepsis models will allow evaluation of the contribution of persistent inflammation in disease progression and outcomes.