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Updated: Jun 19, 2026

Intravenous Endotoxin Challenge in Healthy Humans: An Experimental Platform to Investigate and Modulate Systemic Inflammation
Published on: May 16, 2016
Pretreatment with stress cortisol enhances the human systemic inflammatory response to bacterial endotoxin
Mark P Yeager1, Athos J Rassias, Patricia A Pioli
1Department of Anesthesiology and Medicine, Dartmouth-Hitchcock Medical Center, Lebanon, NH, USA. Mark.P.Yeager@Hitchcock.Org
Objective:
There is continuing controversy regarding the effect of glucocorticoids on a systemic inflammatory process. Based ona model of glucocorticoid action that includes both pro- and anti-inflammatory effects, we used the human experimental endotoxemia model to test the hypothesis that a transient elevation of plasma cortisol to stress-associated levels would enhance a subsequent (delayed) systemic inflammatory response to bacterial endotoxin.
Design:
Prospective, randomized, double-blind, placebo-controlled clinical investigation.
Setting:
Academic medical center.
Subjects:
Thirty-six healthy human volunteers.
Interventions:
Participants were randomized to receive a 6-hr intravenous infusion of saline (control), an intermediate dose of cortisol (Cort80; 6.3 mg/hr/70 kg), or a high dose of cortisol (Cort160; 12.6 mg/hr/70 kg) on day 1. On day 2, participants received an intravenous injection of 2 ng/kg Escherichia coli endotoxin followed by serial measurements of plasma cytokine concentrations.
Measurements And Main Results:
Baseline participant characteristics and cortisol and cytokine concentrations were similar in all three groups. The plasma cortisol response to endotoxemia on day 2 was similar in all three groups. The interleukin-6 response to endotoxemia was significantly increased in the Cort80 Group compared with the control Group (p = .004), whereas the interleukin-10 response was significantly suppressed (p = .034). Corresponding results for the Cort160 Group were not significantly different from control Group values.
Conclusions:
In this study, transient elevation of in vivo cortisol concentrations to levels that are observed during major systemic stress enhanced a subsequent, delayed in vivo inflammatory response to endotoxin. This appeared to be a dose-dependent effect that was more prominent at intermediate concentrations of cortisol than at higher concentrations of cortisol.
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