A Possible Therapeutic Role for Adenosine During Inflammation
- Conditions
- Endotoxemia
- Interventions
- Registration Number
- NCT00513110
- Lead Sponsor
- Radboud University Medical Center
- Brief Summary
The adenosine receptor is known for its anti-inflammatory actions and could therefore be a potential target in the treatment of sepsis and septic shock. Stimulation of the adenosine receptor could potentially lead to a decrease in inflammation and tissue damage.
Under normal conditions adenosine is formed either by an intracellular 5'nucleotidase, which dephosphorylates AMP, or by the hydrolysis of S-adenosylhomcysteine by hydrolase. An alternative pathway of AMP degradations is provided by the cytosolic enzyme AMP deaminase (AMPD), which catalyses the irreversible deamination of AMP to inosine monophosphate and ammonia.
In humans four AMPD isoforms have been described, named after the source from which they were initially purified; M (muscle), L (liver), E1 and E2 (erythrocyte), encoded by AMPD1, AMPD2 and AMPD3. Approximately 15-20% of Caucasian and African American individuals are heterozygous or homozygous for the 34C\>T variant of AMPD1.
We hypothesize that healthy volunteers who have the polymorphism for AMPD1 have a less severe inflammatory response to LPS and show less (severe) organ failure. This hypothesis is based on the expected higher levels of adenosine in patients with the AMPD1 polymorphism. This hypothesis is strengthened by the fact that patients with coronary artery disease and the AMPD1 polymorphism show improved cardiovascular survival (Anderson JL et al. J Am Coll Cardiol 2000; 36: 1248-52) possibly based on higher adenosine levels by reduced AMPD activity. Furthermore the polymorphism predicts improved clinical outcome in patients with heart failure (Loh E et al. Circulation 1999) also based on a hypothetical elevation of adenosine.
We hypothesize that:
The C34T-polymorphism of the enzyme AMP-deaminase leads to a decreased inflammatory respons and thereby a decrease of LPS-induced tissue damage.
A second hypothesis is based on the antagonism of the adenosine receptor, by caffeine;
Antagonism of the adenosine receptor by caffeine leads to an increased LPS-induced inflammatory reaction and an increase in (subclinical) tissue damage?
- Detailed Description
Not available
Recruitment & Eligibility
- Status
- COMPLETED
- Sex
- Male
- Target Recruitment
- 33
- Healthy male volunteers
- Drug-, nicotine-, alcohol abuses
- Tendency towards fainting
- Relevant medical history
Study & Design
- Study Type
- INTERVENTIONAL
- Study Design
- PARALLEL
- Arm && Interventions
Group Intervention Description 1 AMPD1 polymorphism Endotoxin and AMPD1 polymorphism 2 Caffeine infusion Endotoxin and intervention with caffeine 3 placebo Endotoxin combined with placebo
- Primary Outcome Measures
Name Time Method Hemodynamics; heart rate variability 24 hrs after LPS administration Markers of Inflammation 24 hrs after LPS administration Cytokines 24 hrs after LPS administration Sensitivity to norepinephrine 24 hrs after LPS administration Endothelial-dependent and independent vasorelaxation 24 hrs after LPS administration Mediators of Vascular reactivity 24 hrs after LPS administration Markers of endothelial damage and circulating endothelial cells 24 hrs after LPS administration Urinary excretion of markers of renal injury 24 hrs after LPS administration Neurologic testing 24 hrs after LPS administration Adenosine and related nucleotide concentrations. 24 hrs after LPS administration Additional blood samples will be drawn for measurement of: TLR-expression, Genetics; micro array analyses and determination of intercellular signalling pathways. 24 hrs after LPS administration
- Secondary Outcome Measures
Name Time Method
Trial Locations
- Locations (1)
Radboud University Nijmegen Medical Centre
🇳🇱Nijmegen, Gelderland, Netherlands