Introduction: Although the effects of relatively high concentrations of endotoxin on endothelial activation/dysfunction and kidney markers has been described in literature, detailed insight in the LPS concentration-effect relationship, the magnitude, variability and timing of the response, and potential effects of endotoxemia on the kidneys is lacking. A study was performed to assess the effects of low-to moderate dose (0.5, 1 or 2 ng/kg) endotoxemia on the endothelium and kidneys as measured by a panel of novel highly sensitive kidney injury markers. Methods: This was a randomized, double-blind, placebo-controlled study with single ascending doses of LPS (0.5, 1 or 2 ng/kg) administered to healthy male volunteers (3 cohorts of 8 subjects, LPS: placebo 6: 2). Endothelial measures included selectins, cell adhesion molecules, and thrombomodulin. Renal measures included novel, sensitive and specific biomarkers of acute kidney injury. Results: Endotoxin exposure resulted in consistent LPS dose-dependent responses in inflammatory markers, E- and P-Selectin, VCAM1, ICAM1, and thrombomodulin. The observed biological responses were transient, reaching a level of significance of at least