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Trial record 19 of 1208 for:    adenosine

Adenosine and A2A Receptors in Human Brown Adipose Tissue (AdenoBAT)

The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been evaluated by the U.S. Federal Government. Read our disclaimer for details. Identifier: NCT03327168
Recruitment Status : Completed
First Posted : October 31, 2017
Last Update Posted : November 6, 2017
University of Bonn
Information provided by (Responsible Party):
Kirsi Virtanen, Turku University Hospital

Brief Summary:

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

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.

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Study Type : Interventional  (Clinical Trial)
Actual Enrollment : 11 participants
Allocation: Non-Randomized
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

Resource links provided by the National Library of Medicine

Drug Information available for: Adenosine

Arm Intervention/treatment
Active Comparator: Adenosine
Perfusion is measured using PET/CT during intravenous infusion (0.14 mg/kg/min) of adenosine.
Drug: 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.

Primary Outcome Measures :
  1. BAT perfusion [ Time Frame: Effect within 10 minutes ]
    Perfusion of BAT with [15O]-H2O PET-CT

  2. A2A receptor density in BAT [ Time Frame: Effect within 3 hours ]
    Density of A2A receptors in BAT measured with [11C]-TMSX PET/CT

Information from the National Library of Medicine

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Ages Eligible for Study:   18 Years to 40 Years   (Adult)
Sexes Eligible for Study:   Male
Accepts Healthy Volunteers:   Yes

Inclusion Criteria:

  1. Male sex
  2. BMI 20 - 28 kg/m2
  3. Age: 18- 40 years
  4. Normal OGTT
  5. Healthy, no regular medication

Exclusion Criteria:

  1. BMI < 20 kg/m2 or BMI > 28 kg/m2
  2. Low or high blood pressure
  3. Asthma or other obstructive lung disease
  4. Sick sinus syndrome, prolonged QT-interval, or any heart disease
  5. Any chronic disease that could affect the study outcome, including diabetes
  6. Mental disorder or poor compliance
  7. Eating disorder or excessive use of alcohol, tobacco smoking or drug use
  8. Past dose of radiation
  9. 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

Information from the National Library of Medicine

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 identifier (NCT number): NCT03327168

Sponsors and Collaborators
Turku University Hospital
University of Bonn
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Principal Investigator: Kirsi A Virtanen, MD, PhD Turku University Hospital
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Responsible Party: Kirsi Virtanen, Adjunct Professor, Turku University Hospital Identifier: NCT03327168    
Other Study ID Numbers: T201/2015
First Posted: October 31, 2017    Key Record Dates
Last Update Posted: November 6, 2017
Last Verified: October 2017
Individual Participant Data (IPD) Sharing Statement:
Plan to Share IPD: No

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Studies a U.S. FDA-regulated Drug Product: No
Studies a U.S. FDA-regulated Device Product: No
Keywords provided by Kirsi Virtanen, Turku University Hospital:
Adipose Tissue, Brown
Additional relevant MeSH terms:
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Sensory System Agents
Peripheral Nervous System Agents
Physiological Effects of Drugs
Anti-Arrhythmia Agents
Vasodilator Agents
Purinergic P1 Receptor Agonists
Purinergic Agonists
Purinergic Agents
Neurotransmitter Agents
Molecular Mechanisms of Pharmacological Action