Premium
Evaluation of the inhibition of choline uptake in synaptosomes by capillary electrophoresis with electrochemical detection
Author(s) -
Barkhimer Tatyana V.,
Kirchhoff Jon R.,
Hudson Richard A.,
Messer William S.
Publication year - 2002
Publication title -
electrophoresis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.666
H-Index - 158
eISSN - 1522-2683
pISSN - 0173-0835
DOI - 10.1002/1522-2683(200211)23:21<3699::aid-elps3699>3.0.co;2-e
Subject(s) - capillary electrophoresis , chromatography , chemistry , electrophoresis , synaptosome , choline , biochemistry , in vitro
A direct method for evaluating choline uptake by the high‐affinity choline transport system in synaptosomes was developed using capillary electrophoresis (CE) with electrochemical (EC) detection. On‐column EC detection of choline and the internal standard, butyrylcholine, was accomplished with a 25 νm platinum electrode modified with the enzymes, choline oxidase and acetylcholinesterase. Choline uptake was evaluated as a function of choline concentration and a K M value of 1.7 ν M was determined. The method was also used to evaluate a new class of redox affinity inhibitors of choline transport. In particular, the effectiveness of 3‐[(trimethylammonio)methyl]catechol (TMC) as an inhibitor of choline uptake was examined independently and relative to the inhibition of the well‐known inhibitor of choline transport, hemicholinium‐3. The IC 50 and K I for TMC were determined to be 30 ν M and 14 ν M , respectively. The combination of the selectivity and sensitivity afforded by CEEC provides a relatively straightforward approach for monitoring choline transport in synaptosomes.