Table of Contents
Metal-Based Drugs
Volume 6 (1999), Issue 6, Pages 329-336
http://dx.doi.org/10.1155/MBD.1999.329

Tc-Glutathione Complex (Tc -GSH) : Labelling, Chemical Characterization and Biodistribution in Rats

1Université Paris Nord, Laboratoire de Biophysique Expérimentale et Radiopharmacologie, UPRES 2360, UFR Santé Médecine Biologie Humaine, 74, rue M. Cachin, Bobigny cedex 93018, France
2Nuklearmedizinische Klinik und Poliklinik, Ismaninger Strabe 22, München D-81675, Germany
3Hacettepe University, Medical Center, Ankara, Turkey

Received 8 June 1999; Revised 25 June 1999; Accepted 23 August 1999

Copyright © 1999 Hindawi Publishing Corporation. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

The chemical structure of T99mc -GSH has been estabilished using the T99c isotope. Labeling of glutathione with technetium in the presence of stanous chloride gave a high yield result. In a comparative study between T99c and T99mc glutathione, the Tc-GSH complex obtained was purified and characterized by uv, visible spectroscopy, HPLC, Biogel chromatography, mass and NMR spectroscopy. Stoichiometric analysis showed a 2 : 1 molar ratio of GSH/Tc for the reaction. The molecular mass assessed by mass spectroscopy was 727 Da corresponding to an oxo(bis) glutathione technetate. NMR studies demonstrated that each glutathione molecule was coordinated to technetium via cysteinyl sulfur and nitrogen atoms. The biodistribution of the complex was studied in normal rats. Blood clearance was rapid during the first hour involving a biexponential curve ( t1/2 (1) : 50 min, t1/2 (2) : 400 min ). No radioactive accumulation was found in any specific organ except kidney and bladder. All the activity excreted was found unchanged in urine. In conclusion, Tc-GSH displayed an anionic dimer form as GSH-Tc-GSH. We assume that the complex is a tetradentate (2N,2S) complex containing a pentavalent technetium coordinated by two thiol and nitrogen atoms of both GSH ligands, and an apical oxo group.