Technetium radiopharmaceuticals: chemical characterization and tissue distribution of Tc-glucoheptonate using Tc-99m and carrier Tc-99.
The chemical structure of the kidney- and brain-imaging agent Tc-99m glucoheptonate has been established using the Tc-99 isotope. In a comparative study between Tc-99 and Tc-99m glucoheptonates, chromatographic, electrophoretic, and tissue distribution studies showed identical compounds in 0.9% NaCl. Optimal conditions for the formation of the Tc-99 glucoheptonate complex were investigated by uv and visible spectroscopy. The oxidation state of Tc-99 in the compound is V, measured by Sn2+ titration. The complex contains a Tc = O core and two glucoheptonate ligands (oxobis(glucoheptonato)technetate(V) anion (net charge: -1) in aqueous solution). NMR studies demonstrated two five-membered glucoheptonate rings, bidentate bound to Tc by the oxygens of the end carboxyl group and the adjacent hydroxyl group. The compound is stabilized by interaction between Tc-99 and one of the hydroxyloxygens of glucoheptonate at the vacant coordination site trans to the Tc = O core. Experiments with the reducing agent NaBH4 demonstrated the absence of Sn (II or IV) in the complex and a biological behavior independent of the reducing agent used.
D000818:Animals; D002855:Chromatography, Thin Layer; D004588:Electrophoresis, Cellulose Acetate; D007668:Kidney / Q000000981:diagnostic imaging; D008099:Liver / Q000000981:diagnostic imaging; D015609:Organotechnetium Compounds; D011868:Radioisotopes / Q000378:metabolism*; D011877:Radionuclide Imaging; D051381:Rats; D012965:Sodium Chloride; D013400:Sugar Acids / Q000378:metabolism*; D013667:Technetium / Q000378:metabolism*; D014018:Tissue Distribution
D015609:Organotechnetium Compounds; D011868:Radioisotopes; D013400:Sugar Acids; D012965:Sodium Chloride; D013667:Technetium; C100014:technetium Tc 99m gluceptate