Brain uptake of the acid metabolites of F-18-labeled WAY 100635 analogs.

The 5-HT1A ligands [ 18F]FPWAY and [ 18F]FCWAY are metabolized to [ 18F]fluorobenzoic acid (FB) and [ 18F]fluorocyclohexanecarboxylic acid (FC), respectively. To quantify the penetration of these acids into the brain, dynamic positron emission tomography studies were performed in rhesus monkeys with [ 18F]FB and [ 18F]FC. High-performance liquid chromatography analysis of arterial blood samples showed no metabolites for [ 18F]FB, whereas [ 18F]FC was rapidly metabolized to [ 18F]fluoride.

Brain incorporation of [11C]arachidonic acid in young healthy humans measured with positron emission tomography.

Arachidonic acid (AA) is an important second messenger involved in signal transduction mediated by phospholipase A2. The goal of this study was to establish an in vivo quantitative method to examine the role of AA in this signaling process in the human brain. A simple irreversible uptake model was derived from rat studies and modified for positron emission tomography (PET) to quantify the incorporation rate K* of [11C]AA into brain.