title: Biodistribution and kinetic studies of technetium-99m labeled Naja naja karachiensis venom via gamma scintigraphic and SPECT images.
abstract: Naja naja karachiensis have been responsible for plentiful deaths in Pakistan. To investigate bio distribution and blood kinetics, venom was labeled with the radiotracer (technetium-99m) by following the method of direct labeling technique. Its maximum labeling percentage was 97.7% (pH 6, 100 µg stannous chloride dihydrate) which was higher than some other reported venom. Radio labeled venom was stable for more than 4 hours both in vivo (96%) and in vitro (serum 94.1%, saline 94.3%) experimentations. Intravenous doses of venom (250 µg, 0.5 mCi) were found to be evenly distributed (having R/L ratio=1.0) in all parts of sacrificed rabbits. Kidneys (53.75% activity/g) and urinary bladder (23.70% activity/g) were found with the copious quantity of injected dose of venom. Rest of all other organs was found with subsequent remaining dose of venom. Among them, lungs (14.2% activity/g), liver (4.32% activity/g), bones (1.38% activity/g), heart (0.8% activity/g), blood (0.56% activity/g), skin (0.45% activity/g), intestines (0.35% activity/g), skeleton muscles (0.3% activity/g), brain (0.14% activity/g) and stomach (0.05% activity/g) are included. After 24 hours of injection, poisoned blood of rabbits was almost cleared from venom. Gamma scintigraphic images (up to 2 hours) along with bio distribution suggest that kidneys are main organs of excretion in rabbits. Elimination started immediately after administration of venom however, possible sites for metabolism of venom are liver and lungs. More accumulation of venom in heart compared to brain suggests its higher affinity (thus possible higher toxicity) to cardiac muscles as compared to brain tissues.
authors.affiliation: Department of Pharmaceutical Sciences, COMSATS Institute of Information Technology, Abbottabad, Pakistan.
authors.forename: Muhammad Hassham-Hassan
authors.initials: MH
authors.lastname: Bin-Asad
authors.affiliation: Department of Nuclear medicine (MINAR), Nishtar Hospital, Multan, Pakistan.
authors.forename: Durr
authors.initials: D
authors.lastname: e-Sabih
authors.affiliation: Department of Nuclear medicine (MINAR), Nishtar Hospital, Multan, Pakistan.
authors.forename: Israr
authors.initials: I
authors.lastname: Ahmad
authors.affiliation: Department of Nuclear medicine (MINAR), Nishtar Hospital, Multan, Pakistan.
authors.forename: Bashir Ahmad
authors.initials: BA
authors.lastname: Choudhry
authors.affiliation: Department of Nuclear medicine (MINAR), Nishtar Hospital, Multan, Pakistan.
authors.forename: Ghulam
authors.initials: G
authors.lastname: Murtaza
authors.affiliation: Department of Pharmaceutical Sciences, COMSATS Institute of Information Technology, Abbottabad, Pakistan.
authors.forename: Izhar
authors.initials: I
authors.lastname: Hussain
mesh_terms: D000818:Animals; D004546:Elapid Venoms / Q000493:pharmacokinetics*; D017815:Elapidae; D005720:Gamma Rays; D007700:Kinetics; D008297:Male; D011817:Rabbits; D011877:Radionuclide Imaging; D013667:Technetium / Q000493:pharmacokinetics*; D014018:Tissue Distribution; D015899:Tomography, Emission-Computed, Single-Photon
chemical_list: D004546:Elapid Venoms; D013667:Technetium