title: New methodology for pancreatic scintiscanning imaging using 125I-L-3 Iodo-alpha-Methyl Tyrosine.
abstract: The difficulty of a reliable diagnosis of pancreatic diseases by scintiscanning, is mainly derived from the lack of adequate radiopharmaceuticals. With this purpose 125I-L-3 Iodo-a-Methyl Tyrosine (125I-IMT) has been studied, which has also been used for the diagnosis of different kind of brain tumors. The purpose of this work is the development of a quick and easy method for the synthesis and purification of the 125I-IMT in order to be used in a Nuclear Medicine Service. The L-alpha-Methyl Tyrosine was labeled with 125I using I-/I03 and afterwards purified by an anionic exchange resin. The labeling yield obtained was (96.0 +/- 0.5)% when the incubation time was 15 minutes. No significant statistical differences were observed when the incubation time was extended to 1 hour. Biodistribution studies in mice show that the percentage of activity concentration in pancreas is (34.24 +/- 14.03)% at 15 minutes post injection, remaining constant for 30 minutes. The pancreas/liver ratio 15 minutes after the injection of the labeled product was (12.22 +/- 3.59) and it remained constant for 45 minutes more. These results show that 125I-IMT can be used as a diagnostic agent for pancreatic diseases. Since 123I was not available at the moment, this new methodology was developed with 125I.
authors.affiliation: Radioisotope Laboratory, Facultad de Farmacia y Bioquímica, Buenos Aires, Argentina. postmastgradioqui.ffyb.uba.ar
authors.forename: M B
authors.initials: MB
authors.lastname: Zubillaga
authors.forename: J R
authors.initials: JR
authors.lastname: Bocciot
authors.forename: A
authors.initials: A
authors.lastname: Gentile
authors.forename: A E
authors.initials: AE
authors.lastname: Mitta
authors.forename: J O
authors.initials: JO
authors.lastname: Nicolini
authors.forename: R A
authors.initials: RA
authors.lastname: Caro
mesh_terms: D000704:Analysis of Variance; D000818:Animals; D003952:Diagnostic Imaging; D004590:Electrophoresis, Paper; D007457:Iodine Radioisotopes; D008781:Methyltyrosines; D051379:Mice; D010190:Pancreatic Neoplasms / Q000000981:diagnostic imaging*; D011877:Radionuclide Imaging
chemical_list: D007457:Iodine Radioisotopes; D008781:Methyltyrosines