PT  - JOURNAL ARTICLE
AU  - Seok Rye Choi
AU  - Daniel Skovronsky
AU  - Franz Hefti
AU  - A Carpenter
AU  - Geoffrey Golding
AU  - Zhi-Ping Zhuang
AU  - Nathaniel Lim
AU  - Tyler Benedum
AU  - Wei Zhang
AU  - H Kung
TI  - F-18 AV-45 (florpiramine F-18): A PET imaging agent for mapping beta-amyloid plaques in the brain
DP  - 2009 May 01
TA  - Journal of Nuclear Medicine
PG  - 1190--1190
VI  - 50
IP  - supplement 2
4099  - http://jnm.snmjournals.org/content/50/supplement_2/1190.short
4100  - http://jnm.snmjournals.org/content/50/supplement_2/1190.full
SO  - J Nucl Med2009 May 01; 50
AB  - 1190 Objectives Beta-amyloid plaques in the brain is a major risk factor for Alzheimer’s disease. AV-45 (florpiramine F-18) is a plaques-specific imaging agent currently under a phase III clinical trial. We have fully characterized this tracer using in vitro binding and autoradiography techniques. Methods In vitro binding studies were performed using postmortem control and AD brain homogenates, Autoradiography of human brain sections and pathological staining in the same sections were also performed. Ex vivo autoradiography was performed in transgenic mice with beta-amyloid deposits in the brain. Results In vitro binding studies of AD brain homogenates showed a high binding affinity (Kd = 2-3nM). The Bmax values varied depending on AD samples (ranging from 3,000 to 8,000 fmol/mg protein). In vitro autoradioradiography of AD brain sections showed an excellent mapping of the density and regional localization of beta-amyloid plaques, while control brain exhibited no binding. The same highly localized plaque-staining were obtained using transgenic mice. The presence of plaques in human brain sections was confirmed by staining the same section with thioflavin S (a known plaque-specific dye). Screening of binding to other neuro-receptors or binding sites showed an uniformly low binding affinity, suggesting that the tracer only targets beta-amyloid plaques. Conclusions The results provide support indicating that F-18 AV-45 (florpiramine F-18) is a highly selective tracer for imaging beta-amyloid plaques in the brain. This new agent may be useful for imaging amyloid pathology for differential diagnosis of patients with dementia.