Radiolabeled benzoylcholine derivatives as possible myocardial-imaging agents

Two radioiodinated analogs of benzoylcholine were investigated as possible myocardial-imaging agents. O-([2-125I]Iodobenzoyl)-choline and N-([2-125I]iodobenzoyl)cholamine were prepared by nucleophilic substitution of sodium [125I]iodide for stable iodine in O-(N,N]dimethylaminoethyl)-2-iodobenzoate and N-(N',N'-dimethylaminoethyl)-2-iodobenzamide, respectively, and by methylation with methyl iodide. The in vivo distribution of each compound in mice was determined as a function of time. Favorable heart-to-blood and heart-to-lung ratios were obtained with N-([2-125I]iodobenzoyl)cholamine.