A Possible Therapeutic Role for Adenosine During Inflammation
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?
Study Overview
Status
Status
Conditions
Conditions
Intervention / Treatment
Intervention / Treatment
Study Type
Study Type
Enrollment (Anticipated)
Enrollment
Phase
Phase
- Phase 1
Contacts and Locations
Study Locations
-
-
Gelderland
-
Nijmegen, Gelderland, Netherlands, 6500 HB
- Radboud University Nijmegen Medical Centre
-
-
Participation Criteria
Eligibility Criteria
Eligibility Criteria
Ages Eligible for Study
Accepts Healthy Volunteers
Genders Eligible for Study
Description
Inclusion Criteria:
- Healthy male volunteers
Exclusion Criteria:
- Drug-, nicotine-, alcohol abuses
- Tendency towards fainting
- Relevant medical history
Study Plan
How is the study designed?
Design Details
- Primary Purpose: Prevention
- Allocation: Randomized
- Interventional Model: Parallel Assignment
- Masking: Double
Number of Arms
Arms and Interventions
Participant Group / ArmParticipant Group / Arm |
Intervention / TreatmentIntervention / Treatment |
|---|---|
|
Experimental: 1
Endotoxin and AMPD1 polymorphism
|
Endotoxin 2ng/kg to subjects with a AMPD1 polymorphism
|
|
Experimental: 2
Endotoxin and intervention with caffeine
|
Endotoxin 2ng/kg combined with caffeine.
Caffeine (4mg/kg) is used as an adenosine receptor antagonist.
|
|
Placebo Comparator: 3
Endotoxin combined with placebo
|
Endotoxin 2ng/kg combined with saline infusion (0.9%)
|
What is the study measuring?
Primary Outcome Measures
Primary Outcome Measures
Outcome Measure |
Time Frame |
|---|---|
|
Markers of Inflammation
Time Frame: 24 hrs after LPS administration
|
24 hrs after LPS administration
|
|
Cytokines
Time Frame: 24 hrs after LPS administration
|
24 hrs after LPS administration
|
|
Mediators of Vascular reactivity
Time Frame: 24 hrs after LPS administration
|
24 hrs after LPS administration
|
|
Sensitivity to norepinephrine
Time Frame: 24 hrs after LPS administration
|
24 hrs after LPS administration
|
|
Hemodynamics; heart rate variability
Time Frame: 24 hrs after LPS administration
|
24 hrs after LPS administration
|
|
Endothelial-dependent and independent vasorelaxation
Time Frame: 24 hrs after LPS administration
|
24 hrs after LPS administration
|
|
Markers of endothelial damage and circulating endothelial cells
Time Frame: 24 hrs after LPS administration
|
24 hrs after LPS administration
|
|
Urinary excretion of markers of renal injury
Time Frame: 24 hrs after LPS administration
|
24 hrs after LPS administration
|
|
Neurologic testing
Time Frame: 24 hrs after LPS administration
|
24 hrs after LPS administration
|
|
Adenosine and related nucleotide concentrations.
Time Frame: 24 hrs after LPS administration
|
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.
Time Frame: 24 hrs after LPS administration
|
24 hrs after LPS administration
|
Collaborators and Investigators
Sponsor
Sponsor
Investigators
Investigators
- Principal Investigator: Peter Pickkers, MD,PhD, Radboud University Medical Center
Publications and helpful links
General Publications
- Ramakers BP, Riksen NP, van den Broek P, Franke B, Peters WH, van der Hoeven JG, Smits P, Pickkers P. Circulating adenosine increases during human experimental endotoxemia but blockade of its receptor does not influence the immune response and subsequent organ injury. Crit Care. 2011;15(1):R3. doi: 10.1186/cc9400. Epub 2011 Jan 6.
- van den Boogaard M, Ramakers BP, van Alfen N, van der Werf SP, Fick WF, Hoedemaekers CW, Verbeek MM, Schoonhoven L, van der Hoeven JG, Pickkers P. Endotoxemia-induced inflammation and the effect on the human brain. Crit Care. 2010;14(3):R81. doi: 10.1186/cc9001. Epub 2010 May 5.
Study record dates
Study Major Dates
Study Start
Study Start
Primary Completion (Actual)
Primary Completion
Study Completion (Actual)
Study Completion
Study Registration Dates
First Submitted
First Submitted
First Submitted That Met QC Criteria
First Submitted That Met QC Criteria
First Posted (Estimate)
First Posted
Study Record Updates
Last Update Posted (Estimate)
Last Update Posted
Last Update Submitted That Met QC Criteria
Last Update Submitted That Met QC Criteria
Last Verified
Last Verified
More Information
Terms related to this study
Keywords
Additional Relevant MeSH Terms
- Pathologic Processes
- Infections
- Systemic Inflammatory Response Syndrome
- Sepsis
- Bacteremia
- Toxemia
- Inflammation
- Endotoxemia
- Physiological Effects of Drugs
- Neurotransmitter Agents
- Molecular Mechanisms of Pharmacological Action
- Enzyme Inhibitors
- Purinergic Antagonists
- Purinergic Agents
- Phosphodiesterase Inhibitors
- Purinergic P1 Receptor Antagonists
- Central Nervous System Stimulants
- Caffeine
Other Study ID Numbers
Other Study ID Numbers
- 2007/099
- CMO 2007/099
This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.
Clinical Trials on Endotoxemia
-
NCT04920565RecruitingMultiple Organ Dysfunction With Severe Endotoxemia
-
NCT05570643CompletedSepsis, Endotoxemia, Immunosuppression
-
NCT05260099WithdrawnSuspected or Diagnosed Endotoxemia Casued by Gram-negative Bacteria
-
NCT01176942CompletedMetabolic Syndrome | Metabolic Endotoxemia
-
NCT03860584CompletedMetabolic Syndrome | Metabolic Endotoxemia
-
NCT02521779Completed
-
NCT01100996Completed
Clinical Trials on AMPD1 polymorphism
-
NCT05453188CompletedCOVID-19 | Genetic Predisposition to Disease
-
NCT07542223Active, not recruiting
-
NCT03467828CompletedBronchopulmonary Displasia
-
NCT06457646Not yet recruiting
-
NCT05588817Recruiting
-
NCT00898040CompletedMultiple Myeloma and Plasma Cell Neoplasm
-
NCT07289451CompletedH. Pylori Infection
-
NCT02633475UnknownAbortion, Spontaneous