Preparation, characterization and biodistribution of a new technetium-99m nitrido complex with 2-methoxyisobutylisomtrile and comparison with Tc-99m-MIBI

The preparation of complex (TcN)-Tc-99m-MIBI was carried out using two alternative procedures that led to the formation of the complex with high radiochemical purity (> 90%). The partition coefficient, electrophoresis and cationic resin exchange experiments showed that the (TcN)-Tc-99m-MIBI is a lipophilic and neutral complex, the structure of this complex is six-coordinate distorted octahedral, its composition may be [(TcNCl2)-Tc-99m(MIBI)(3)], and the optimized geometry of this complex was calculated by using Gaussian 98 for Window (G98W) program. The biodistribution of (TcN)-Tc-99m-MIBI shows high myocardial uptake and good target/non-target ratios in mice at early post-injection time, for 5 min post-injection the heart-to-blood, heart-to-lungs and heart-to-liver ratios are 3.18, 1.72 and 1.42, respectively. In respect of the relatively good rations after 5 min and the rapid clearance from non-target, the complex (TcN)-Tc-99m-MIBI may be suitable for instant myocardial imaging. In addition, the lyophilized kit enables the convenient preparation of this complex for clinical use. Based on these promising properties, (TcN)-Tc-99m-MIBI should be a new potential myocardial perfusion-imaging agent. Copyright (C) 2002 John Wiley Sons, Ltd.Biochemical Research MethodsChemistry, MedicinalChemistry, AnalyticalSCI(E)4ARTICLE121029-10434