TY - CHAP AU - Elmenhorst, David AU - Bier, Dirk AU - Holschbach, Marcus AU - Bauer, Andreas TI - Imaging of Adenosine Receptors; Chapter 7 CY - Berlin, Heidelberg PB - Springer Berlin Heidelberg M1 - FZJ-2014-01650 SN - 978-3-642-42013-9 SP - 181-198 PY - 2014 AB - Adenosine is a fundamental molecule of life. It is a part of the DNA and the main degradation product of the central currency of energy metabolism in humans and animals – adenosine triphosphate (ATP). Under pathological conditions like hypoxia, the adenosine concentration can rise severalfold – up to micromolar concentrations. The net effect of adenosine on excitable tissue is inhibitory affecting the release of classical neurotransmitters like glutamate, GABA (gamma-aminobutyric acid), and dopamine. The widely used neurostimulant caffeine exerts its effects as an antagonist at adenosine receptors. Four different types of adenosine receptors have been described in mammals: A1, A2A, A2B, and A3 which are all G-protein-coupled receptors. Over the last 25 years, adenosine receptor ligands, agonists as well as antagonists, have emerged as a class of useful therapeutics. For the A1 and A2A subtypes several antagonist radioligands have been used successfully for PET imaging in humans and animals especially for the brain. LB - PUB:(DE-HGF)7 DO - DOI:10.1007/978-3-642-42014-6_7 UR - https://juser.fz-juelich.de/record/151761 ER -