Cardiac troponin I release and cytokine response during experimental human endotoxaemia

Objective. To study the relationship between cytokine levels and cardiac troponin I (cTnI). Design. Prospective experimental study. Setting. Intensive care unit of a university hospital. Participants. Six healthy male volunteers. Interventions. Endotoxin, 4 ng/kg, was given as a 1-min intravenous infusion. Measurements and results. Circulating cardiac troponin I levels and proinflammatory cytokines tumour necrosis factor-alpha (TNF-alpha), interleukin-6 (IL-6) and interleukin-8 (IL-8) were analysed at various time points during a 24-h period. TNF-alpha appeared in the circulation 30 min after injection (T=0.5 h), reaching peak levels (5,665+/-1,910 pg/ml) 2 h after infusion. At T=24 h TNF-alpha was still elevated in the circulation compared to T=0. None of the six volunteers had a cTnI value higher than 0.1 mug/l at T=0, 6 h or 24 h. Conclusion. The presence of significant amounts of TNF-alpha, IL-6 and IL-8 in the systemic circulation does not lead to increased levels of cTnI in experimental human endotoxaemia.