During sepsis and septic shock the immune response can be overwhelming leading to excessive tissue damage, organ failure and death. Ideally, the inflammatory response is modulated leading to both adequate protection to invading pathogens as well as limitation of an exuberant immune response. In the last few years adenosine is proposed to have a central role in the modulation of inflammation. In unfavorable conditions such as hypoxia, ischemia or inflammation adenosine is quickly up-regulated; with concentrations up to tenfold in septic patients. Many animal studies have shown that adenosine is able to attenuate the inflammatory response and decrease mortality rates. Therefore, pharmacological elevation of the adenosine concentration is an potential target to attenuate inflammation and limit organ injury. Dipyridamole, an adenosine re-uptake inhibitor is able to increase the adenosine concentration and limit ischemia-reperfusion injury. In order to study the effects of dipyridamole on the inflammatory response we aim to use the so called human endotoxemia model. This model permits elucidation of key players in the immune response to a gram negative stimulus in vivo, therefore serving as a useful tool to investigate potential novel therapeutic strategies in a standardized setting.
Study Type
INTERVENTIONAL
Allocation
RANDOMIZED
Purpose
PREVENTION
Masking
TRIPLE
Enrollment
30
Oral treatment with dipyridamole 200 mg twice daily during seven consecutive days
Placebo twice daily during seven consecutive days
The LPS derived from E. coli O:113 2ng/kg iv will be injected in 1 minute at a dosage of 2 ng/kg body weight.
Radboud University Nijmegen Medical Centre
Nijmegen, Netherlands
Circulating cytokines
TNFx, IL6, IL10, IL1RA
Time frame: 24 hours after LPS administration
Hemodynamics
Continious heart rate and blood pressure measurement
Time frame: 24 hours after LPS administration
Sensitivity to norepinephrine
Venous occlusion plethysmography
Time frame: 24 hrs after LPS administration
Endothelial-dependent and independent vasorelaxation
Venous occlusion plethysmography
Time frame: 24 hours after LPS administration
Markers of endothelial damage and circulating endothelial cells
circulating adhesion molecules (ICAM, VCAM, E-selectin, P-selectin) circulating endothelial cells
Time frame: 24 hrs after LPS administration
Urinary excretion of markers of renal injury
GSTAlpha1-1 and GSTPi1-1
Time frame: 24 hrs after LPS administration
Adenosine and related nucleotide concentrations
Time frame: 24 hrs after LPS administration
Additional blood samples will be drawn for genetic testing and measurement of: mRNA and proteins part of the adenosine metabolism
Time frame: 24 hours after LPS administration
Oxydative stress
Thiols, neutrophilic burst, calcium release of neuthrophils, TBARS, Carbonyls, FRAP, Myeloperoxidase, catalase, Griess assay
Time frame: 24 hours after LPS administration
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