title: 99mTc-labeling studies of a modified metronidazole and its biodistribution in tumor bearing animal models.
abstract: A cysteine-based bifunctional chelating agent viz. N-(2'-hydroxybenzyl)-cysteine with a free carboxylic acid group (CAA) was synthesized. Bearing in mind the affinity of localization of nitroimidazoles in hypoxic tissues, this bifunctional chelating agent was coupled to metronidazole (MNZ). The (99m)Tc labeling studies of the novel agent (MNZCAA) thus obtained, was carried out and the radiolabeled product was subsequently purified. The complexation yield under optimized condition was approximately 85%. Biodistribution studies carried out in Swiss mice bearing 'barcl-95' tumors showed selective accumulation of the injected activity in the tumor (1.70%/g at 30 min p.i.) with renal as well as hepatobiliary clearance. High tumor/muscle ratio (14.7 at 3 h post-injection) of the novel agent indicates considerable promise towards further evaluation.
authors.affiliation: Radiopharmaceuticals Division, Bhabha Atomic Research Centre, Mumbai 400085, India.
authors.forename: Tapas
authors.initials: T
authors.lastname: Das
authors.forename: Sharmila
authors.initials: S
authors.lastname: Banerjee
authors.forename: Grace
authors.initials: G
authors.lastname: Samuel
authors.forename: H D
authors.initials: HD
authors.lastname: Sarma
authors.forename: Aruna
authors.initials: A
authors.lastname: Korde
authors.forename: Meera
authors.initials: M
authors.lastname: Venkatesh
authors.forename: M R A
authors.initials: MR
authors.lastname: Pillai
mesh_terms: D000818:Animals; D005260:Female; D007553:Isotope Labeling / Q000379:methods; D008223:Lymphoma / Q000000981:diagnostic imaging* / Q000378:metabolism*; D008657:Metabolic Clearance Rate; D008795:Metronidazole / Q000031:analogs & derivatives / Q000493:pharmacokinetics*; D051379:Mice; D009368:Neoplasm Transplantation; D009928:Organ Specificity; D011877:Radionuclide Imaging; D019275:Radiopharmaceuticals / Q000138:chemical synthesis / Q000493:pharmacokinetics; D017556:Technetium Compounds / Q000493:pharmacokinetics*; D013953:Thymus Neoplasms / Q000000981:diagnostic imaging / Q000378:metabolism; D014018:Tissue Distribution; D014407:Tumor Cells, Cultured
chemical_list: D019275:Radiopharmaceuticals; D017556:Technetium Compounds; D008795:Metronidazole