Modified “4 + 1” Mixed Ligand Technetium-Labeled Fatty Acids for Myocardial Imaging: Evaluation of Myocardial Uptake and Biodistribution

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• 作者：Peter Mirtschink ; Sebastian N. Stehr ; Hans J. Pietzsch ; Ralf Bergmann ; Jens Pietzsch ; Gerd Wunderlich ; Anke C. Heintz ; Joachim Kropp ; Hartmut Spies ; Werner Kraus ; Andreas Deussen ; Martin Walther
• 刊名：Bioconjugate Chemistry
• 出版年：2008
• 出版时间：January 2008
• 年：2008
• 卷：19
• 期：1
• 页码：97 - 108
• 全文大小：649K
• 年卷期：v.19,no.1(January 2008)
• ISSN：1520-4812

文摘

Our group previously synthesized ^99mTc-labeled fatty acids suitable for myocardial metabolism and flow imaging. In this set of experiments, 29 new analogues were synthesized according to the “4 + 1” mixed ligand approach with some specific differences. Conventional “4 + 1” ^99mTc-fatty acids are built in the sequence: Tc-chelate, alkyl chain, and carboxylic group. We developed compounds following a new design with the sequence: carboxylic group, alkyl chain, Tc-chelate, and lipophilic tail. Therefore, the ^99mTc-chelate was transferred to a more central position of the compound, aiming toward an improved myocardial profile and an accelerated liver clearance. In this context, several functional groups incorporated in the lipophilic tail section were tested to evaluate their influence on the compound's character. In addition to biodistribution studies in vivo, the myocardial first-pass extraction of the compounds was tested in an isolated Langendorff rat heart model. A satisfactory myocardial uptake of up to 20% of the injected dose (% ID) in the perfused heart and a fast liver clearance in vivo with only 0.29% ID/g at 60 min postinjection demonstrate that the induced molecular modifications affect the kinetics of ^99mTc-radiolabeled fatty acid compounds favorably. From the data set, rules for estimating the biodistribution of fatty acids tracers are deduced.