News | November 02, 2012

Caffeine’s Effect on Brain’s Adenosine Receptors Visualized for First Time

Scans allow researchers to study link between caffeine and neurodegenerative disorders

November 2, 2012 – Molecular imaging with positron emission tomography (PET) has enabled scientists for the first time to visualize binding sites of caffeine in the living human brain to explore possible positive and negative effects of caffeine consumption. According to research published in the November issue of The Journal of Nuclear Medicine, PET imaging with F-18-8-cyclopentyl-3-(3-fluoropropyl)-1-propylxanthine (F-18-CPFPX) shows that repeated intake of caffeinated beverages throughout a day results in up to 50 percent occupancy of the brain’s A1 adenosine receptors.

“The effects of caffeine to the human body are generally attributed to the cerebral adenosine receptors. In the human brain the A1 adenosine receptor is the most abundant,” said David Elmenhorst, M.D., lead author of “Caffeine Occupancy of Human Cerebral A1 Adenosine Receptors: In Vivo Quantification with F-18-CPFPX and PET.” “In vitro studies have shown that commonly consumed quantities of caffeine have led to a high A1 adenosine occupancy. Our study aimed to measure the A1 adenosine receptor occupancy with in vivo imaging.”

Fifteen male volunteers participated in the study. They abstained from caffeine intake for 36 hours and then underwent a PET scan with F-18-CPFPX. Caffeine was then introduced in short intravenous infusions, increasing in amount. To estimate the occupancy of A1 adenosine receptors by caffeine, the distribution volume at the baseline period of the PET scan was compared with the distribution volume after caffeine administration. Researchers determined that the concentration of the caffeine that displaces 50 percent of the binding of F-18-CPFPX to the A1 adenosine receptor was 13 mg/L, or approximately four to five cups of coffee.

An important finding of the study is that in most regular coffee drinkers, about half of the A1adenosine receptors may be occupied by caffeine. It is likely that this blockage of a substantial amount of cerebral A1 adenosine receptors will result in adaptive changes and lead to chronic alterations of receptor express and availability.

“There is substantial evidence that caffeine is protective against neurodegenerative diseases like Parkinson’s or Alzheimer’s disease,” noted Elmenhorst. “Several investigations show that moderate coffee consumption of three to five cups per day at mid-life is linked to a reduced risk of dementia in late life. The present study provides evidence that typical caffeine doses result in a high A1adenosine receptor occupancy and supports the view that the A1 adenosine receptor deserves broader attention in the context of neurodegenerative disorders.”

Caffeine is the most commonly consumed psychoactive substance worldwide and an active ingredient in innumerable food and beverages. Eighty percent of U.S. adults consume caffeine every day; the average for adults is 200 mg of caffeine per day (two 5-ounce cups of coffee or four sodas). It affects an individual’s alertness, attention, cognitive performance, as well as reduces sleepiness.

Authors of the article “Caffeine Occupancy of Human Cerebral A1 Adenosine Receptors: In Vivo Quantification with 18F-CPFPX and PET” include David Elmenhorst, Andres Matusch and Oliver H. Winz, Institute of Neuroscience and Medicine (INM-2), Forschungszentrum Juelich, Juelich, Germany; Phillip T. Meyer, Institute of Neuroscience and Medicine (INM-2), Forschungszentrum Juelich, Juelich, Germany and Department of Nuclear Medicine, University Hospital, Freiburg, Freiburg, Germany; and Andreas Bauer, Institute of Neuroscience and Medicine (INM-2), Forschungszentrum Juelich, Juelich, Germany and Department of Neurology, Medical Faculty, Heinrich-Heine-University Duesseldorf, Duesseldorf, Germany.

For more information: www.snmmi.org

Related Content

News | Business | September 19, 2017
September 19, 2017 — Invicro LLC, a provider of imaging services and software for research and drug development, anno
ScImage and Invia Partnership Announced
News | PACS | September 19, 2017
ScImage Inc. and Invia Imaging Solutions recently announced formation of a joint partnership at the American Society of...
Theraclion to Launch Metastatic Breast Cancer Trial Combining Echotherapy and Immunotherapy
News | Focused Ultrasound Therapy | September 18, 2017
September 18, 2017 — Theraclion and co-lead investigator David Brenin, M.D., from the University of Virginia School o
Toshiba Highlights Latest CT Advancements at RSNA 2017
News | Computed Tomography (CT) | September 18, 2017
Toshiba Medical announced that it will display several new enhancements to its existing computed tomography (CT)...
Philips Launches CardioMD IV Cardiac SPECT Solution at ASNC 2017
Technology | SPECT Imaging | September 15, 2017
September 15, 2017 — Philips highlighted its newest solution for...
Double Targeting Ligands to Identify and Treat Prostate Cancer

The mice were imaged with small-animal PET/CT using 124I-RPS-027 (7.4 MBq [200 μCi]). Credit: JM Kelly et al., Department of Radiology, Weill Cornell Medicine, New York, NY

News | Prostate Cancer | September 14, 2017
Researchers have demonstrated a new, effective way to precisely identify and localize prostate cancer tumors while...
Blue Earth Diagnostics Announcing Results of FALCON PET/CT Trial at ASTRO 2017
News | PET-CT | September 13, 2017
September 13, 2017 — Blue Earth Diagnostics announced the upcoming oral presentation of initial results from the FALC
Delphinus Enrolls First Patient in Discover Breast Ultrasound Clinical Project
News | Ultrasound Womens Healthcare | September 08, 2017
September 8, 2017 — Delphinus Medical Technologies Inc.
Overlay Init