Neurochemical Characterization of an Antimony‐Choline Analog in Rat Cortical Synaptosomes

Abstract
An analog of choline, in which nitrogen was replaced by antimony, was neurochemically characterized in rat cortical synaptosomes. It was found to be a substrate for several cholinergic enzymes, transported by a Na+‐dependent, hemicholinium‐3‐sensitive process, acetylated, and subsequently released by depolarization in a calcium‐dependent manner. Sb‐choline also competed with choline for Na+‐dependent uptake and for acetylation by [14C]acetyl‐CoA in synaptosomes. These results suggest that Sb‐choline and its acetylated product should be useful substrates for the x‐ray microanalytical localization of cholinergic pools in intact nerve terminals.