PT  - JOURNAL ARTICLE
AU  - Jin Song
AU  - Zehui Wu
AU  - Seok Choi
AU  - Karl Ploessl
AU  - Hank Kung
TI  - A potential imaging agent for aromatase: 4-[[(4-iodophenyl)methyl]-4H-1,2,4-triazol-4-ylamino]-benzonitrile
DP  - 2016 May 01
TA  - Journal of Nuclear Medicine
PG  - 1334--1334
VI  - 57
IP  - supplement 2
4099  - http://jnm.snmjournals.org/content/57/supplement_2/1334.short
4100  - http://jnm.snmjournals.org/content/57/supplement_2/1334.full
SO  - J Nucl Med2016 May 01; 57
AB  - 1334Objectives Aromatase is the time-limiting enzyme catalyzing the biosynthesis of estrogens, which involved in many physiological processes and diseases. This enzyme is widely distributed in many organs including gonadal tissues, stomach and brain. Imaging agents based on aromatase inhibitors would be useful tools for studying its function in the brain and peripheral tissues.Methods A series of aromatase inhibitors, aminobenzonitril derivatives, were prepared and screened. Among them, 4-[[(4-[125I]iodophenyl)methyl]-4H-1,2,4-triazol-4-ylamino]-benzonitrile, 1, was prepared and tested in rats.Results In vitro binding studies showed that these aromatase inhibitors exhibited very high binding affinity (IC50 = 0.04 - 0.32 nM). Biodistribution of [125I]1 in rats showed high uptake in stomach and ovary. Autoradiography of rat brain displayed highly specific uptake and retention in the bed nucleus of the stria terminalis and amygdala, areas known to have high density of aromatase. The regional brain uptakes were completely blocked by a pre-treatment with (s)-vorozole, a known aromatase inhibitor.Conclusions 4-[[(4-[125I]iodophenyl)methyl]-4H-1,2,4-triazol-4-ylamino]-benzonitrile, -[125I]1, was prepared. Results of biological studies suggest that it may be useful for in vivo imaging of aromatase in the brain or other peripheral organs or tissues.$$graphic_{748378CB-51CD-4F5E-A978-93074F609E2C}$$