Biological evaluation of 5-methyl-branched-chain omega-[18F]fluorofatty acid: a potential myocardial imaging tracer for positron emission tomography.
5-Methyl-17-[18F]fluoroheptadecanoic acid (5-MFHA) has been proposed as a new myocardial imaging tracer for positron emission tomography (PET), containing methyl-branching at the odd-numbered position, except the 3-position. To compare the site of methyl-branching of fatty acids on the contribution to myocardial imaging, the biological evaluation of 5-MFHA-using accumulation studies, metabolic studies, and PET studies of the heart muscle-was investigated. In the comparative biodistribution studies for 16-[18F]fluoropalmitic acid (FPA), 3-methyl-17-[18F]fluoroheptadecanoic acid (3-MFHA) and 5-MFHA, the initial myocardial uptake of 5-MFHA (2.64 [%dose/g tissue]) was relatively high between those of FPA and 3-MFHA (3.45 and 1.58, respectively), and the washout from myocardium of 5-MFHA was midway between those of FPA and 3-MFHA. In the lipid analysis studies, 5-MFHA was mainly metabolized to triglycerides in the myocardium, and its metabolic pattern was similar to that of straight-chain fatty acids (FPA). In the PET studies using 5-MFHA in canines, good myocardial images were obtained for up to 30 min after injection.
Takahashi
T
T
Division of Radiopharmaceutical Chemistry, Cyclotron and Radioisotope Center Tohoku University, Sendai, Japan.
Nishimura
S
S
Ido
T
T
Ishiwata
K
K
Iwata
R
R
D000818:Animals; D004285:Dogs; D004655:Emulsions; D005227:Fatty Acids / Q000493:pharmacokinetics*; D005230:Fatty Acids, Nonesterified / Q000493:pharmacokinetics*; D005462:Fluorine Radioisotopes; D006321:Heart / Q000000981:diagnostic imaging*; D007553:Isotope Labeling / Q000379:methods; D009206:Myocardium / Q000378:metabolism*; D010169:Palmitic Acids / Q000493:pharmacokinetics*; D051381:Rats; D013329:Structure-Activity Relationship; D014018:Tissue Distribution; D014055:Tomography, Emission-Computed / Q000379:methods*
D004655:Emulsions; D005227:Fatty Acids; D005230:Fatty Acids, Nonesterified; D005462:Fluorine Radioisotopes; D010169:Palmitic Acids; C068739:17-fluoro-3-methylheptadecanoic acid; C102273:5-methyl-17-fluoroheptadecanoic acid; C038460:6-fluoropalmitic acid