title: Synthesis and biological evaluation of a new type of 99mtechnetium-labeled Fatty Acid for myocardial metabolism imaging.
abstract: Technetium-labeled fatty acids intended for myocardial metabolism imaging and the respective rhenium model complexes were synthesized according to the "4 + 1" mixed-ligand approach and investigated in vitro and in vivo. The non-radioactive rhenium model complexes were characterized by NMR, IR, and EA, and the geometrical impact of the chelate unit on the integrity of the fatty acid head structure was determined by single-crystal X-ray analyses. To estimate the diagnostic value of the 99mTc-labeled fatty acids, the compounds were investigated in experiments in vitro and in biodistribution studies using male Wistar rats. The new fatty acid tracers contain the metal core in the oxidation states +3, well-wrapped in a trigonal-bipyramidal coordination moiety, which is attached at the omega-position of a fatty acid chain. This structural feature is considered to be a good imitation of the well-established iodinated phenyl fatty acids. High heart extraction in perfused heart studies (up to 26% injected dose (ID)) and noticeable heart uptake of the 99mTc tracers in vivo being in the order of 2% ID/g at 5 min (postinjection, pi.), accompanied by a good heart to blood ratio of 8, confirms that the new Tc compounds are suitable as fatty acid tracers.
authors.affiliation: Institute of Radiopharmacy, Research Center Dresden-Rossendorf, PF 510119, D-01314 Dresden, Germany. m.walther@fzd.de
authors.forename: Martin
authors.initials: M
authors.lastname: Walther
authors.forename: Christian M
authors.initials: CM
authors.lastname: Jung
authors.forename: Ralf
authors.initials: R
authors.lastname: Bergmann
authors.forename: Jens
authors.initials: J
authors.lastname: Pietzsch
authors.forename: Katrin
authors.initials: K
authors.lastname: Rode
authors.forename: Karim
authors.initials: K
authors.lastname: Fahmy
authors.forename: Peter
authors.initials: P
authors.lastname: Mirtschink
authors.forename: Sebastian
authors.initials: S
authors.lastname: Stehr
authors.forename: Anke
authors.initials: A
authors.lastname: Heintz
authors.forename: Gerd
authors.initials: G
authors.lastname: Wunderlich
authors.forename: Werner
authors.initials: W
authors.lastname: Kraus
authors.forename: Hans-Juergen
authors.initials: HJ
authors.lastname: Pietzsch
authors.forename: Joachim
authors.initials: J
authors.lastname: Kropp
authors.forename: Andreas
authors.initials: A
authors.lastname: Deussen
authors.forename: Hartmut
authors.initials: H
authors.lastname: Spies
mesh_terms: D000818:Animals; D003300:Copper / Q000737:chemistry; D018360:Crystallography, X-Ray; D005227:Fatty Acids / Q000138:chemical synthesis / Q000737:chemistry* / Q000378:metabolism* / Q000493:pharmacokinetics; D006321:Heart / Q000187:drug effects; D008024:Ligands; D008297:Male; D008958:Models, Molecular; D015394:Molecular Structure; D009206:Myocardium / Q000378:metabolism*; D051381:Rats; D017208:Rats, Wistar; D017550:Spectroscopy, Fourier Transform Infrared; D013667:Technetium / Q000737:chemistry*
chemical_list: D005227:Fatty Acids; D008024:Ligands; D013667:Technetium; D003300:Copper