Inflammation
Conditions
Keywords
Adenosine, Cytokines, Inflammation, VEGF
Brief summary
The purpose of this study is to extend previous observations in animal models regarding the effects of adenosine in the release of cytokines to human subjects. We intend to accomplish this in two study protocols. In the first we will infuse intravenously adenosine and measure the plasma levels of inflammatory cytokines. In the second one, we will use a microdialysis technique to infuse intradermally small amounts of adenosine and will measure skin blood flow and will take a biopsy to measure levels of mRNA for cytokines.
Detailed description
In Protocol 1 we will infuse adenosine at a dose of 80 mcg/kg/min for 30 minutes while measuring plasma levels of adenosine at different time points, ranging from 30 minutes to 6 hours. Because activation of A2B receptors also mediates the release of inflammatory cytokines, including IL-6, samples will be taken to measure these and other inflammatory/angiogenic cytokines. In a second protocol, we will administer adenosine intradermically via a microdialysis probe for 30 minutes while we measure the local effect on skin blood flow using laser Doppler techniques. One hour after the end of the infusion we will obtain a skin biopsy from the perfused area for measurement of mRNA for VEGF, IL-8, IL-6 and other cytokines. In addition, we foresee the possibility of further testing looking for and genetic association between angiogenesis and adenosine. These are proof-of-concept pilot studies. We will study up to 12 subjects in each protocol but an interim analysis will be performed after 6 subjects are studied. This will help us determine if a trend is observed, to perform power calculations, and determine if more extensive studies are warranted.
Interventions
DRUGAdenosine
IV infusion of adenosine at a dose of 80 mcg/kg/min for 30 minutes.
DRUGSodium Nitroprusside
To compare the effects of adenosine on increasing cytokines, sodium nitroprusside will be infused at 5 mcg/kg/min (a dose expected to produce similar systemic effects to adenosine)
Sponsors
Vanderbilt University
Study design
Allocation
NON_RANDOMIZED
Intervention model
SINGLE_GROUP
Primary purpose
OTHER
Masking
SINGLE (Subject)
Eligibility
Sex/Gender
ALL
Age
18 Years to 60 Years
Healthy volunteers
Yes
Inclusion criteria
* Age 18-60 yr. * All potential volunteers will have routine blood test to screen for hepatic, renal, and hematological abnormalities. * Body mass index \< 27 Kg/m2 . * Female volunteers of childbearing potential will undergo HCG pregnancy test at screening and again on the study day.
Exclusion criteria
* Pregnancy females * Subjects unable to give voluntary informed consent * Subjects on anticoagulant drugs or anemic * Subjects with a recent medical illness * Subjects with a history of coronary heart disease * Subjects with known kidney or liver disease * Subjects with history of asthma * Recent (past three days) use of phosphodiesterase type 5 (PDE5) inhibitors (sildenafil, tadalafil or vardenafil) * History of intolerance to adenosine or nitroprusside * History of methemoglobinemia * Use of theophylline products * Subjects with hematological abnormalities
Design outcomes
Primary
| Measure | Time frame |
|---|---|
| Plasma levels of cytokines | 6 hours |
Countries
United States
Outcome results
None listed