A simple and efficient in vitro method for metabolism studies of radiotracers

In vitro metabolism of acetylcholinesterase inhibitors containing 3-[F-18]f luoromethylbenzyl-([F-18]1) and 4-[F-18]fluorobenzyl-piperidine moieties ([ F-18]2) was studied and compared with the in vivo metabolism. Defluorinatio n of the [F-18]1 mainly occurred to generate [F-18]fluoride ion both in vit ro and in vivo, In contrast, the [F-18]2 was converted into an unknown pola r metabolite in both metabolism methods and another metabolite, 4-[F-18]flu orobenzoic acid in vitro. These results demonstrated that the in vitro meth od can be used to predict the in vivo metabolism of both radiotracers. (C) 2001 Elsevier Science Inc. All rights reserved.