title: 8-cyclopentadienyltricarbonyl 99mtc 8-oxooctanoic acid: a novel radiotracer for evaluation of medium chain fatty acid metabolism in the liver.
abstract: 8-Cyclopentadienyltricarbonyl 99mTc 8-oxooctanoic acid (99mTc-CpTTOA; 1a) was synthesized for evaluation of medium chain fatty acid metabolism in the liver. 99mTc-CpTTOA was prepared in high radiochemical yield (50-63%) by a double ligand transfer reaction of methyl 8-ferrocenyl-8-oxooctanoate and Na99mTcO4 in the presence of CrCl3 and Cr(CO)6, followed by hydrolysis. This radiotracer was shown to be stable (>90% at 6 h) when incubated with human serum. Aqueous extraction of the radioactivity from the liver and blood samples of mice suggested that 99mTc-CpTTOA was mainly metabolized via beta-oxidation in the liver, and the radioactivity was retained longer in CCl4-treated mice than in control mice, possibly due to impaired beta-oxidation in the former. Planar images of rats injected with 99mTc-CpTTOA showed accumulation of the radioactivity in the liver, kidneys, and bladder with rapid hepatic clearance as a function of time. Analysis of the metabolites from the liver and urine samples of rats further supported that 99mTc-CpTTOA was metabolized to 4-cyclopentadienyltricarbonyl 99mTc 4-oxobutanoic acid (99mTc-CpTTBA; 1c) via beta-oxidation. The results suggested that this radiotracer might be of valuable use in the evaluation of fatty acid metabolism in the liver.
authors.affiliation: Department of Nuclear Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, 50 Ilwon-dong, Kangnam-ku, Seoul 135-710, Korea.
authors.forename: Byung Chul
authors.initials: BC
authors.lastname: Lee
authors.forename: Yearn Seong
authors.initials: YS
authors.lastname: Choe
authors.forename: Dae Yoon
authors.initials: DY
authors.lastname: Chi
authors.forename: Jin-Young
authors.initials: JY
authors.lastname: Paik
authors.forename: Kyung-Han
authors.initials: KH
authors.lastname: Lee
authors.forename: Yong
authors.initials: Y
authors.lastname: Choi
authors.forename: Byung-Tae
authors.initials: BT
authors.lastname: Kim
mesh_terms: D000818:Animals; D002210:Caprylates / Q000138:chemical synthesis* / Q000493:pharmacokinetics*; D002252:Carbon Tetrachloride Poisoning / Q000000981:diagnostic imaging / Q000378:metabolism; D004355:Drug Stability; D005227:Fatty Acids / Q000378:metabolism*; D006801:Humans; D007091:Image Processing, Computer-Assisted; D066298:In Vitro Techniques; D007202:Indicators and Reagents; D008099:Liver / Q000000981:diagnostic imaging* / Q000378:metabolism*; D009682:Magnetic Resonance Spectroscopy; D008297:Male; D051379:Mice; D008813:Mice, Inbred ICR; D015609:Organotechnetium Compounds / Q000138:chemical synthesis* / Q000493:pharmacokinetics*; D019275:Radiopharmaceuticals / Q000138:chemical synthesis* / Q000493:pharmacokinetics*; D051381:Rats; D017207:Rats, Sprague-Dawley; D012997:Solvents; D014055:Tomography, Emission-Computed
chemical_list: C482338:8-cyclopentadienyltricarbonyltechnetium-8-oxooctanoic acid; D002210:Caprylates; D005227:Fatty Acids; D007202:Indicators and Reagents; D015609:Organotechnetium Compounds; D019275:Radiopharmaceuticals; D012997:Solvents