Synthesis and Cerebral Uptake of 1-(1-[11C]Methyl-1H-pyrrol-2-yl)-2-phenyl-2-(1-pyrrolidinyl)ethanone, a Novel Tracer for Positron Emission Tomography Studies of Monoamine Oxidase Type A.

( R)-(−)- and ( S)-(+)-1-(1-[ 11C]methyl-1 H-pyrrol-2-yl)-2-phenyl-2-(1-pyrrolidinyl)ethanone 4and 5were synthesized, and their properties as tracers for positron emission tomography (PET) studies of monoamine oxidase type A (MAO-A) in the brain of living pigs were tested. Parametric maps of the distribution volume ( Vd) 4in pig brain were qualitatively similar to those obtained with [ 11C]harmine, with prominent binding in the ventral forebrain and mesencephalon. Its binding was highly vulnerable to MAO blockade, suggesting a binding potential as high as 2 for MAO-A sites. The slow plasma metabolism of 4and 5may present advantages over [ 11C]harmine for routine PET studies of MAO-A. [ABSTRACT FROM AUTHOR]