Adenosine and A2A Receptors in Human Brown Adipose Tissue (AdenoBAT)
Adenosine and A2a Receptors in Human Brown Adipose Tissue (AdenoBAT)
This study investigates the significance of adenosine and A2A receptors in human brown adipose tissue (BAT) in vivo. Using positron emission tomography (PET), perfusion and the density of A2A receptors will be measured in supraclavicular BAT and other tissues in healthy men. The investigators hypothesize, that adenosine can activate BAT, and that adenosine A2A receptor density changes when BAT is activated by cold exposure.
Understanding the mechanisms of BAT activation and the role of endocannabinoids in humans is important and beneficial in fighting against the epidemic of obesity and diabetes.
Study Overview
Status
Status
Conditions
Conditions
Intervention / Treatment
Intervention / Treatment
Detailed Description
Adenosine is a purine nucleoside released locally in BAT when noradrenaline and ATP are released from sympathetic nerves. Recently it was found that adenosine activates murine and human brown adipocytes, and recruits beiging of white fat via adenosine A2A receptors (A2AR). Furthermore, studies with mice have shown improvements in glucose homeostasis after administration of A2AR agonists.
In this study the investigators use the PET radiotracer [15O]-H2O to quantify perfusion of BAT, white adipose tissue (WAT) and muscle in three conditions: room temperature, cold exposure and intravenous infusion of adenosine. Another PET radiotracer [11C]TMSX is used to quantify adenosine A2A receptor density of BAT, WAT and muscle in room temperature and during cold exposure.
Study Type
Study Type
Enrollment (Actual)
Enrollment
Phase
Phase
- Not Applicable
Participation Criteria
Eligibility Criteria
Eligibility Criteria
Ages Eligible for Study
Accepts Healthy Volunteers
Genders Eligible for Study
Description
Inclusion Criteria:
- Male sex
- BMI 20 - 28 kg/m2
- Age: 18- 40 years
- Normal OGTT
- Healthy, no regular medication
Exclusion Criteria:
- BMI < 20 kg/m2 or BMI > 28 kg/m2
- Low or high blood pressure
- Asthma or other obstructive lung disease
- Sick sinus syndrome, prolonged QT-interval, or any heart disease
- Any chronic disease that could affect the study outcome, including diabetes
- Mental disorder or poor compliance
- Eating disorder or excessive use of alcohol, tobacco smoking or drug use
- Past dose of radiation
- Any other condition that in the opinion of the investigator could create a hazard to the subject safety, endanger the study procedures or interfere with the interpretation of study results
Study Plan
How is the study designed?
Design Details
- Primary Purpose: Basic Science
- Allocation: Non-Randomized
- Interventional Model: Crossover Assignment
- Masking: None (Open Label)
Number of Arms
Arms and Interventions
Participant Group / ArmParticipant Group / Arm |
Intervention / TreatmentIntervention / Treatment |
|---|---|
|
Active Comparator: Adenosine
Perfusion is measured using PET/CT during intravenous infusion (0.14 mg/kg/min) of adenosine.
|
Intravenous infusion of adenosine (0.14 mg/kg) is administered for 5 minutes during PET/CT scan.
Other Names:
|
|
No Intervention: Room temperature
Perfusion and A2A receptor density is measured using PET/CT in resting room temperature conditions.
|
|
|
Experimental: Cold exposure
Perfusion and A2A receptor density is measured using PET/CT during controlled cold exposure.
|
Controlled cold exposure is performed before and during PET/CT scan.
|
What is the study measuring?
Primary Outcome Measures
Primary Outcome Measures
Outcome Measure |
Measure Description |
Time Frame |
|---|---|---|
|
BAT perfusion
Time Frame: Effect within 10 minutes
|
Perfusion of BAT with [15O]-H2O PET-CT
|
Effect within 10 minutes
|
|
A2A receptor density in BAT
Time Frame: Effect within 3 hours
|
Density of A2A receptors in BAT measured with [11C]-TMSX PET/CT
|
Effect within 3 hours
|
Collaborators and Investigators
Sponsor
Sponsor
Collaborators
Collaborators
Investigators
Investigators
- Principal Investigator: Kirsi A Virtanen, MD, PhD, Turku University Hospital
Study record dates
Study Major Dates
Study Start (Actual)
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 (Actual)
First Posted
Study Record Updates
Last Update Posted (Actual)
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
Other Study ID Numbers
Other Study ID Numbers
- T201/2015
Plan for Individual participant data (IPD)
Plan to Share Individual Participant Data (IPD)?
Drug and device information, study documents
Studies a U.S. FDA-regulated drug product
Studies a U.S. FDA-regulated device product
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