Synthesis, purification, and time-dependent disposition studies of 9- or 10-mono-iodostearic acid and 9- and 10-mono-iodostearyl carnitine

The purpose of this investigation was to evaluate the potential use of radiolabeled 9- or 10-mono-iodostearyl carnitine as a perfusion and metabolic imaging agent for the heart. Radiochemical purity was achieved and determined by the use of silica gel and/or anion exchange resin chromatography. Radiochemical yields of 45-63 and 4% were obtained for the fatty acid and carnitine ester, respectively. Male albino mice were sacrificed at 2, 5, 7, 10, 15, 20, 30, and 50 minutes post-injection with either 125I 9- or 10-mono-iodostearic acid or 9- or 10-mono-iodostearyl (-) carnitine. The lungs, liver heart, kidney, spleen, pancreas, small intestine, stomach, thyroid, blood, fat, and skeletal muscle tissue were excised and assayed for levels of radioactivity in a NaI crystal well counter. The very low target-to-nontarget ratios obtained with 125I 9- or 10-mono-iodostearyl carnitine in mice strongly suggest that radioiodinated 9- or 10-mono-iodostearyl carnitine is not suitable for use as a myocardial imaging agent. However, radioiodinated 9- or 10-mono-iodostearic acid showed promise as a myocardial imaging agent and may warrant further investigation