Creating a reproducible and valid method for adenosine measurement
ID
Source
Brief title
Condition
- Myocardial disorders
- Ancillary infectious topics
Synonym
Research involving
Sponsors and support
Intervention
Outcome measures
Primary outcome
Adenosine concentrations
Secondary outcome
forearm bloodflow (vasodilatation/vasoconstriction)
Background summary
Adenosine, a degradation product of adenosinetriphosphate (ATP) accumulates in
many tissues following hypoxia, ischemia and inflammation. Known as the
*retaliatory* metabolite adenosine is able to modulate several physological
processes.
Adenosine is formed both extracellular as intracellular by dephosphorylation of
adenosinemonophosphate (AMP) by 5*-nucleotidase. The degradation of adenosine
is mainly intracellular, through adenosine deaminase and adenosine kinase. The
equilibrative nucleoside transporter (ENT) controles facillitated diffusion
between extra- and intracellular adensoine.
Over the past 60 years adenosine measurement has proven to be an extremely
difficult task. With a half life of approximately 1 second adenosine is rapidly
taken up and metabolised by erythrocytes.
In this study we describe an optimized method for the detection of adenosine in
blood. First, a syringe system enables us to withdraw blood and deliver blocker
solution to the sample at the same time. Secondly, a blocker solution
consisting of an adenosine re-uptake inhibitor, deaminase inhibitor, kinase
inhibitor and a 5`-nucleotidase inhibitor, paralyses the adenosine metabolism.
In order to create a reproducable and valid method for adenosine measurement we
tested blood several times within the same subject. Furthermore we used the
cold pressor test (CPT) as a local vasoconstrictor-inducing stimulus to
increase plasma levels of adenosine. Treatment with the well-known adenosine
re-uptake inhibitor dipyridamole was used to create higher levels of plasma
adenosine.
Study objective
Creating a reproducible and valid method for adenosine measurement
Study design
methodological
Intervention
Cold Pressor test:
The volunteers left hand will be held in ice water for 2 minutes
Forearm Bloodflow will be measured by venous occlusion plethysmography.
Study burden and risks
Time: screening 20 minutes
experiments day 1 and 7: 210 minutes
Bloodsampling: venous infusion on day 1 and 7 in both arms
Bloedcollection: total bloodsampling 50 ml.
Dipyridamole: Subjects will use dipyridamole for 7 days (twice daily Persantin
retard 200 mg). The *safety-analysis* ESPS-2 study showed that this
concentration is safe, besides a headache no other adverse effects are to be
expected. There are no health riks involved in the use of dipyridamole.
Postbus 9101
6500 HB Nijmegen
Nederland
Postbus 9101
6500 HB Nijmegen
Nederland
Listed location countries
Age
Inclusion criteria
No medical history
No medication
age 18-35 years
non-smokers
Exclusion criteria
medical history
hypertension
Design
Recruitment
Medical products/devices used
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In other registers
Register | ID |
---|---|
EudraCT | EUCTR2007-001930-15-NL |
CCMO | NL17446.091.07 |