title: Preparation of (131)I-Pyrimethamine and evaluation for scintigraphy of experimentally Toxoplasma gondii-infected rats.
abstract: We aimed to assess the ability of (131)I-Pyrimethamine scintigraphy to detect the lesions of Toxoplasma gondii infection. An experimental model of toxoplasmosis was developed. The presence of toxoplasmosis was confirmed 60 days after implantation. Pyrimethamine was radioiodinated with I-131. The radioligand was validated by the requisite quality control tests to check its radiolabeling efficiency, in vitro stability and radiochemical purity etc. (131)I-Pyrimethamine (specific activity: 7.08 MBq/µmol) was injected intravenously into the tail vein of the control and infected rats. Static whole body images of the rats were acquired under the gamma camera at 5 min, 45 min, 2 h, 6 h, and 24 h following the intravenous administration of the radioactivity (3.7 MBq/rat). Then the scintigraphic data were analyzed both visually and semiquantitatively. Regions of interest (ROIs) were drawn over the organs (thyroid, stomach, liver, bladder, and soft tissues) to calculate the ratios of the radiotracer in infected vs. control rats. The mean ratio of radiotracer in infected/control rats in the liver and diaphragm was over 1 at 45 min which persisted till 24 h. In conclusion, (131)I-Pyrimethamine may be useful agent for diagnosis toxoplasmosis especially involving liver and diaphragm, needs further preclinical validation before being extended for use in clinical applications.
authors.affiliation: Department of Parasitology, Dokuz Eylul University, School of Medicine, Inciralti, Izmir, Turkey. tonay.inceboz@gmail.com
authors.forename: Tonay
authors.initials: T
authors.lastname: Inceboz
authors.forename: Fatma
authors.initials: F
authors.lastname: Yurt Lambrecht
authors.forename: Erdem
authors.initials: E
authors.lastname: Surucu
authors.forename: Osman
authors.initials: O
authors.lastname: Yilmaz
authors.forename: Altug
authors.initials: A
authors.lastname: Yavasoglu
authors.forename: Kubra
authors.initials: K
authors.lastname: Durkan
authors.forename: Başak
authors.initials: B
authors.lastname: Baykara
authors.forename: Recep
authors.initials: R
authors.lastname: Bekis
authors.forename: Ahmet
authors.initials: A
authors.lastname: Uner
mesh_terms: D000818:Animals; D000981:Antiprotozoal Agents / Q000737:chemistry / Q000493:pharmacokinetics; D004195:Disease Models, Animal; D004339:Drug Compounding; D004355:Drug Stability; D007457:Iodine Radioisotopes; D011739:Pyrimethamine / Q000737:chemistry / Q000493:pharmacokinetics; D011877:Radionuclide Imaging; D051381:Rats; D017208:Rats, Wistar; D014018:Tissue Distribution; D014122:Toxoplasma / Q000302:isolation & purification*; D014124:Toxoplasmosis, Animal / Q000000981:diagnostic imaging* / Q000469:parasitology; D051598:Whole Body Imaging
chemical_list: D000981:Antiprotozoal Agents; D007457:Iodine Radioisotopes; D011739:Pyrimethamine