Adenosine and A2A Receptors in Human Brown Adipose Tissue (AdenoBAT)
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|ClinicalTrials.gov Identifier: NCT03327168|
Recruitment Status : Completed
First Posted : October 31, 2017
Last Update Posted : November 6, 2017
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.
|Condition or disease||Intervention/treatment||Phase|
|Obesity||Drug: Adenosine Other: Cold exposure||Not Applicable|
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 :||Interventional (Clinical Trial)|
|Actual Enrollment :||11 participants|
|Intervention Model:||Crossover Assignment|
|Intervention Model Description:||Each subject participates in PET/CT scans in room temperature conditions, during cold exposure and during i.v. infusion of adenosine.|
|Masking:||None (Open Label)|
|Primary Purpose:||Basic Science|
|Official Title:||Adenosine and A2a Receptors in Human Brown Adipose Tissue (AdenoBAT)|
|Actual Study Start Date :||November 1, 2015|
|Actual Primary Completion Date :||June 30, 2016|
|Actual Study Completion Date :||June 30, 2016|
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 Name: Adenocor
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.
Other: Cold exposure
Controlled cold exposure is performed before and during PET/CT scan.
- BAT perfusion [ Time Frame: Effect within 10 minutes ]Perfusion of BAT with [15O]-H2O PET-CT
- A2A receptor density in BAT [ Time Frame: Effect within 3 hours ]Density of A2A receptors in BAT measured with [11C]-TMSX PET/CT
To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.
Please refer to this study by its ClinicalTrials.gov identifier (NCT number): NCT03327168
|Principal Investigator:||Kirsi A Virtanen, MD, PhD||Turku University Hospital|