Synthesis and bioevaluation of [18F]4-fluoro-m-hydroxyphenethylguanidine ([18F]4F-MHPG): A novel radiotracer for quantitative PET studies of cardiac sympathetic innervation
作者:Keun Sam Jang、Yong-Woon Jung、Phillip S. Sherman、Carole A. Quesada、Guie Gu、David M. Raffel
DOI:10.1016/j.bmcl.2013.01.106
日期:2013.3
A new cardiac sympathetic nerve imaging agent, [F-18]4-fluoro-m-hydroxyphenethylguanidine ([F-18]4F-MHPG), was synthesized and evaluated. The radiosynthetic intermediate [F-18]4-fluoro-m-tyramine ([F-18]4F-MTA) was prepared and then sequentially reacted with cyanogen bromide and NH4Br/NH4OH to afford [F-18]4F-MHPG. Initial bioevaluations of [F-18]4F-MHPG (biodistribution studies in rats and kinetic studies in the isolated rat heart) were similar to results previously reported for the carbon-11 labeled analog [C-11]4F-MHPG. The neuronal uptake rate of [F-18]4F-MHPG into the isolated rat heart was 0.68 ml/min/g wet and its retention time in sympathetic neurons was very long (T-1/2 > 13 h). A PET imaging study in a nonhuman primate with [F-18]4F-MHPG provided high quality images of the heart, with heart-to-blood ratios at 80-90 min after injection of 5-to-1. These initial kinetic and imaging studies of [F-18]4F-MHPG suggest that this radiotracer may allow for more accurate quantification of regional cardiac sympathetic nerve density than is currently possible with existing neuronal imaging agents. (C) 2013 Elsevier Ltd. All rights reserved.