Adenosine and A2a Receptors in Human Brown Adipose Tissue (AdenoBAT)
试验速览
- 阶段
- 不适用
- 状态
- 已完成
- 入组人数
- 11
- 主要终点
- BAT perfusion
研究概览
简要总结
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.
详细描述
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.
研究设计
- 研究类型
- Interventional
- 分配方式
- Non Randomized
- 干预模型
- Crossover
- 主要目的
- Basic Science
- 盲法
- None
入排标准
- 年龄范围
- 18 Years 至 40 Years（Adult）
- 性别
- Male
- 接受健康志愿者
- 是
入选标准
- •BMI 20 - 28 kg/m2
- •Age: 18- 40 years
- •Normal OGTT
- •Healthy, no regular medication
排除标准
- •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
研究组 & 干预措施
Adenosine
Perfusion is measured using PET/CT during intravenous infusion (0.14 mg/kg/min) of adenosine.
干预措施: Adenosine (Drug)
Cold exposure
Perfusion and A2A receptor density is measured using PET/CT during controlled cold exposure.
干预措施: Cold exposure (Other)
结局指标
主要结局
BAT perfusion
时间窗: Effect within 10 minutes
Perfusion of BAT with \[15O\]-H2O PET-CT
A2A receptor density in BAT
时间窗: Effect within 3 hours
Density of A2A receptors in BAT measured with \[11C\]-TMSX PET/CT
次要结局
未报告次要终点
研究者
Kirsi Virtanen
Adjunct Professor
Turku University Hospital