Evaluation of radioiodinated (-)-o-iodovesamicol as a radiotracer for mapping the vesicular acetylcholine transporter.

Article date: 2003/10/25

PubMed ID: 14575378

Journal name: Annals of nuclear medicine (ISSN: 0914-7187)


We evaluated the potencies of radioiodinated (-)-o-iodovesamicol [(-)-oIV] as a selective vesicular acetylcholine transporter (VAChT) mapping agent. (-)-[125I]oIV exhibited significant accumulation (about 2.8% of the injected dose) in rat brain. The regional brain distribution of radioactivity was similar for both (-)-[125I]olV and (-)-[3H]vesamicol. The accumulation of (-)-[125I]oIV in the brain was significant reduced by post-administration of unlabeled vesamicol (0.5 /micromol/kg(-1)) and (-)-oIV (0.5 micromol/kg(-1)). On the other hand, the post-administration of sigma ligands hardly affected the accumulation of (-)-[125I]oIV in the brain. These studies showed that (-)-[125I]oIV, as well as [3H] vesamicol, bound to VAChT with high affinity in the rat brain. Furthermore, (-)-[125I]oIV binding in the ipsilateral cortex to the lesion was significantly reduced by 17.0%, compared with that in the contralateral cortex in a unilateral NBM-lesioned rat. These results suggested that radioiodinated (-)-oIV may potentially be useful for the diagnosis of cholinergic neurodegenerative disorders.

Author List: Shiba Kazuhiro, Mori Hirofumi, Tonami Norihisa

Publication Types: Comparative Study; Evaluation Studies; Journal Article; Research Support, Non-U.S. Gov't; Validation Studies

Substances mentioned in the article: Carrier Proteins; Iodine Radioisotopes; Membrane Transport Proteins; Piperidines; Radiopharmaceuticals; Slc18a3 protein, rat; Vesicular Acetylcholine Transport Proteins; Vesicular Transport Proteins; Ibotenic Acid; vesamicol;

Mesh terms: Animals; Brain/diagnostic imaging; Carrier Proteins/metabolism; Ibotenic Acid; Iodine Radioisotopes/chemistry; Isotope Labeling/methods; Male; Membrane Transport Proteins; Metabolic Clearance Rate; Neurodegenerative Diseases/chemically induced; Organ Specificity; Piperidines/chemistry; Radionuclide Imaging; Radiopharmaceuticals/chemical synthesis; Rats; Reproducibility of Results; Sensitivity and Specificity; Tissue Distribution; Vesicular Acetylcholine Transport Proteins; Vesicular Transport Proteins;

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