title: Differences in labelled triolein turnover after oral administration between liver and adipose tissue of rats.
abstract: To investigate exogenous triacylglycerol turnover, the time courses for labelled triolein in the liver, plasma and epididymal adipose tissue (adipose tissue) after oral administration to rats fed a fat-free or 10 % corn oil diet for 3 d after fasting overnight were examined for 10 d. After the administration of labelled triolein to rats fed the fat-free diet, the incorporation (dpm/g) into total lipids of the liver and adipose tissue each reached the maximum in 8 h and was seven times higher in the adipose tissue than in the liver. The half-lives of total lipid radioactivities during the decreasing phases were 0.39 and 2.58 d, respectively, in the rapid and slow phases of the decay curve in the liver, and 4.78 d in only one phase of the adipose tissue. Radioactivity after administration of labelled triolein was mostly found in the oleic acid in the tissues. The half-life of oleic acid was 3.92 d in the adipose tissues. These half-lives were similar in both dietary groups. Thus, although dietary corn oil reduced the triolein incorporation to cellular lipids in comparison to the fat-free diet, it did not affect these half-lives. The labelled triacylglycerol-oleic acid stayed abundantly intact for a long time in the adipose tissue and was scarcely changed to other fatty acids, whereas it was slightly incorporated into total lipids and quickly metabolized in the liver. Non-essential fatty acids may be mostly endogenous in the liver but may be exogenous and endogenous in adipose tissue.
authors.affiliation: Faculty of Human and Cultural Studies, Tezukayama Gakuin University, 4-Cho, Harumidai, Sakai, Osaka 590-0113, Japan. iritani@hcs.tezuka-gu.ac.jp
authors.forename: Nobuko
authors.initials: N
authors.lastname: Iritani
authors.forename: Tomoe
authors.initials: T
authors.lastname: Kimura
authors.forename: Hitomi
authors.initials: H
authors.lastname: Fukuda
authors.forename: Tomomi
authors.initials: T
authors.lastname: Sugimoto
mesh_terms: D000273:Adipose Tissue / Q000378:metabolism*; D000284:Administration, Oral; D000818:Animals; D002851:Chromatography, High Pressure Liquid; D003314:Corn Oil / Q000494:pharmacology; D005508:Food Deprivation / Q000502:physiology; D006207:Half-Life; D050356:Lipid Metabolism; D008099:Liver / Q000378:metabolism*; D008297:Male; D051381:Rats; D017208:Rats, Wistar; D014280:Triglycerides / Q000378:metabolism; D014304:Triolein / Q000008:administration & dosage / Q000493:pharmacokinetics*
chemical_list: D014280:Triglycerides; D014304:Triolein; D003314:Corn Oil