Comparison of the lymphatic transport of radiolabeled 1,3-dioleoylglycerol and trioleoylglycerol in rats.
It has been reported that, compared with TAG, DAG suppresses postprandial hypertriacylglycerolemia and reduces visceral fat levels in experimental animals and humans. To clarify the mechanism responsible for these beneficial effects, we compared the lymphatic transport of 1,3-DAG, a major isomer of DAG, and TAG in rats. Male SD rats, after insertion of a cannula into the thoracic duct, were given 1,3-di[1-14C]oleoylglycerol or tri[1-14C]oleoylglycerol via a stomach tube. The 24-h recovery of the radioactivity from 1,3-di[14C]oleoylglycerol in the lymph was slightly but significantly lower than that from tri[14C]oleoylglycerol (81.3+/-1.0 vs. 86.5+/-1.2%, respectively). However, in the first 1-h interval after administration, the recovery of radioactivity from 1,3-dioleoylglycerol was almost half of that from trioleoylglycerol (17.5+/-2.0 vs. 31.1+/-1.4%). The amount of TAG and phospholipids secreted into the lymph was significantly lower 1 h after the administration of 1,3-dioleoylglycerol compared with that after the administration of trioleoylglycerol. More than 90% of the radioactivity recovered in the lymph in the first 3 h was distributed in the TAG fraction for both 1,3-dioleoylglycerol and trioleoylglycerol. These results suggest that slower lymphatic transport of 1,3-DAG compared with TAG could be a factor in the suppression of postprandial hypertriacylglycerolemia. The possibility that the slower lymphatic transport of DAG contributes to the anti-obesity action observed in the feeding of 1,3-DAG cannot be excluded.
Yanagita
Teruyoshi
T
Laboratory of Nutrition Biochemistry, Department of Applied Biological Sciences, Saga University, Saga 840-8502, Japan. yanagitt@cc.saga-u.ac.jp
Ikeda
Ikuo
I
Wang
Yu-ming
YM
Nakagiri
Hideaki
H
D000818:Animals; D001692:Biological Transport / Q000502:physiology*; D002250:Carbon Radioisotopes; D002784:Cholesterol / Q000378:metabolism; D004075:Diglycerides / Q000378:metabolism* / Q000493:pharmacokinetics; D050356:Lipid Metabolism; D008198:Lymph Nodes / Q000378:metabolism; D042601:Lymphatic Vessels / Q000378:metabolism*; D008297:Male; D010743:Phospholipids / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D014304:Triolein / Q000378:metabolism* / Q000493:pharmacokinetics
D002250:Carbon Radioisotopes; D004075:Diglycerides; D010743:Phospholipids; D014304:Triolein; D002784:Cholesterol; C013965:diolein