The Effects of Human Endotoxemia on Functional Capacity of Hematopoietic Stem and Progenitor Cells

Inclusion Criteria: * Written informed consent * Age ≥18 and ≤35 yrs * Male * Healthy (as confirmed by medical history, examination, ECG, blood sampling) Exclusion Criteria: * Use of any medication * Smoking * History or signs of atopic syndrome (asthma, rhinitis with medication and/or eczema) * Known anaphylaxis or hypersensitivity to the non-investigational products or their excipients. * History or signs of hematological disease (bone marrow dysfunction): * Thrombocytopenia (\<150\*10\^9/ml) or anemia (hemoglobin \< 8.0 mmol/L) * Abnormalities in leukocyte differential counts * History, signs or symptoms of cardiovascular disease, in particular: * Previous spontaneous vagal collapse * History of atrial or ventricular arrhythmia * Cardiac conduction abnormalities on the ECG consisting of a 2nd degree atrioventricular block or a complete left bundle branch block * Hypertension (defined as RR systolic \> 160 or RR diastolic \> 90) * Hypotension (defined as RR systolic \< 100 or RR diastolic \< 50) * Renal impairment (defined as plasma creatinine \>120 μmol/l) * Liver enzyme abnormalities (above 2x the upper limit of normal) * Medical history of any disease associated with immune deficiency * CRP \> 20 mg/L, WBC \> 12x109/L or \< 4 x109/L, or clinically significant acute illness, including infections, within 3 weeks before labeling day * Previous (participation in a study with) LPS administration * Any vaccination within 3 months prior to labeling day * Participation in a drug trial or donation of blood 3 months prior to labeling day * Recent hospital admission or surgery with general anesthesia (\<3 months to labeling day) * Use of recreational drugs within 21 days prior to labeling day * Inability to personally provide written informed consent (e.g. for linguistic or mental reasons) and/or take part in the study.