Evaluation of [1-11C]octanoate as a new radiopharmaceutical for assessing liver function using positron emission tomography.
[1-11C]Octanoate was evaluated as a new radiopharmaceutical for the evaluation of liver function using positron emission tomography (PET). In biodistribution studies with normal mice, [1-11C]octanoate was rapidly taken up by the liver. [1-11C]Octanoate in the liver was present in the parenchymal cells and was predominantly metabolized via beta-oxidation followed by its rapid clearance. In the CCl4-treated mice, [1-11C]octanoate showed significantly slower hepatic clearance than that in the controls. In PET studies using rats, the time-radioactivity curves in the liver showed a two-phase decrease, and compared with the normal rat, the CCl4-treated rat showed a slower hepatic half-clearance time for the first phase, which is related to beta-oxidation metabolism. A preliminary PET study of [1-11C]octanoate metabolism in a normal volunteer was consistent with these animal studies. The present study showed that metabolism of [1-11C]octanoate in the liver was influenced by beta-oxidation, and it is advantageous to use [1-11C]octanoate clinically as a regional liver-function diagnostic agent in conjunction with PET.
Department of Patho-Functional Bioanalysis, Graduate School of Pharmaceutical Sciences, Kyoto University, Japan.
N
N
Yamamura
Y
Y
Magata
H
H
Kitano
J
J
Konishi
H
H
Saji
D000085:Acetates / Q000493:pharmacokinetics; D000328:Adult; D000818:Animals; D001219:Aspartate Aminotransferases / Q000097:blood; D001711:Biotransformation; D002210:Caprylates / Q000138:chemical synthesis / Q000493:pharmacokinetics; D006801:Humans; D007553:Isotope Labeling; D008099:Liver / Q000000981:diagnostic imaging*; D008111:Liver Function Tests / Q000379:methods*; D008297:Male; D051379:Mice; D010168:Palmitates / Q000493:pharmacokinetics; D019275:Radiopharmaceuticals / Q000138:chemical synthesis / Q000493:pharmacokinetics; D051381:Rats; D017208:Rats, Wistar; D014018:Tissue Distribution; D014055:Tomography, Emission-Computed / Q000379:methods*
D000085:Acetates; D002210:Caprylates; D010168:Palmitates; D019275:Radiopharmaceuticals; D001219:Aspartate Aminotransferases; C031492:octanoic acid