Metabolism of doubly-labeled chylomicron cholesteryl esters in the rat
Chylomicrons labeled in vitro with doubly-labeled cholesteryl esters were injected intravenously into fasted rats, and the tissue distribution and chemical form of each isotope were observed for 24 hr. The use of doubly-labeled cholesteryl esters provided information about the metabolism of both the...
| Main Authors: | , |
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| Format: | Article |
| Language: | English |
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Elsevier
1967-05-01
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| Series: | Journal of Lipid Research |
| Subjects: | |
| Online Access: | http://www.sciencedirect.com/science/article/pii/S0022227520401476 |
| _version_ | 1818728831732678656 |
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| author | Steven H. Quarfordt Dewitt S. Goodman |
| author_facet | Steven H. Quarfordt Dewitt S. Goodman |
| author_sort | Steven H. Quarfordt |
| collection | DOAJ |
| description | Chylomicrons labeled in vitro with doubly-labeled cholesteryl esters were injected intravenously into fasted rats, and the tissue distribution and chemical form of each isotope were observed for 24 hr. The use of doubly-labeled cholesteryl esters provided information about the metabolism of both the sterol and the fatty acid moieties.Similar results were obtained with doubly-labeled cholesteryl palmitate, oleate, and linoleate. In each instance, most (80-90%) of the chylomicron cholesteryl ester was removed from the plasma by the liver; small amounts were also taken up by all other tissues examined. There was no hydrolysis during uptake. In the liver the newly absorbed cholesteryl esters underwent slow hydrolysis (60% after 1 hr and 85-90% after 3.5 hr); the rate of reesterification of the liberated cholesterol was still slower. After 24 hr only 20-28% of the labeled cholesterol present in the animal was found in the liver.Labeled fatty acid disappeared from the liver, and was redistributed among other tissues, much more rapidly than the labeled cholesterol. Most of the labeled fatty acid apparently underwent oxidation, since only 15-20% of the injected labeled fatty acid was present in the animal after 24 hr. At this time the three fatty acids were differently distributed between and within the tissues. These differences reflected some known differences of fatty acid concentration and lipid composition in the various tissues. |
| first_indexed | 2024-12-17T22:36:15Z |
| format | Article |
| id | doaj.art-6b0f5bd0226249ea8fae64860348fa8c |
| institution | Directory Open Access Journal |
| issn | 0022-2275 |
| language | English |
| last_indexed | 2024-12-17T22:36:15Z |
| publishDate | 1967-05-01 |
| publisher | Elsevier |
| record_format | Article |
| series | Journal of Lipid Research |
| spelling | doaj.art-6b0f5bd0226249ea8fae64860348fa8c2022-12-21T21:30:05ZengElsevierJournal of Lipid Research0022-22751967-05-0183264273Metabolism of doubly-labeled chylomicron cholesteryl esters in the ratSteven H. Quarfordt0Dewitt S. Goodman1Department of Medicine, Columbia University College of Physicians and Surgeons, New York 10032Department of Medicine, Columbia University College of Physicians and Surgeons, New York 10032Chylomicrons labeled in vitro with doubly-labeled cholesteryl esters were injected intravenously into fasted rats, and the tissue distribution and chemical form of each isotope were observed for 24 hr. The use of doubly-labeled cholesteryl esters provided information about the metabolism of both the sterol and the fatty acid moieties.Similar results were obtained with doubly-labeled cholesteryl palmitate, oleate, and linoleate. In each instance, most (80-90%) of the chylomicron cholesteryl ester was removed from the plasma by the liver; small amounts were also taken up by all other tissues examined. There was no hydrolysis during uptake. In the liver the newly absorbed cholesteryl esters underwent slow hydrolysis (60% after 1 hr and 85-90% after 3.5 hr); the rate of reesterification of the liberated cholesterol was still slower. After 24 hr only 20-28% of the labeled cholesterol present in the animal was found in the liver.Labeled fatty acid disappeared from the liver, and was redistributed among other tissues, much more rapidly than the labeled cholesterol. Most of the labeled fatty acid apparently underwent oxidation, since only 15-20% of the injected labeled fatty acid was present in the animal after 24 hr. At this time the three fatty acids were differently distributed between and within the tissues. These differences reflected some known differences of fatty acid concentration and lipid composition in the various tissues.http://www.sciencedirect.com/science/article/pii/S0022227520401476cholesteryl estersdoubly-labeledin chylomicronsratplasma clearancehepatic uptake |
| spellingShingle | Steven H. Quarfordt Dewitt S. Goodman Metabolism of doubly-labeled chylomicron cholesteryl esters in the rat Journal of Lipid Research cholesteryl esters doubly-labeled in chylomicrons rat plasma clearance hepatic uptake |
| title | Metabolism of doubly-labeled chylomicron cholesteryl esters in the rat |
| title_full | Metabolism of doubly-labeled chylomicron cholesteryl esters in the rat |
| title_fullStr | Metabolism of doubly-labeled chylomicron cholesteryl esters in the rat |
| title_full_unstemmed | Metabolism of doubly-labeled chylomicron cholesteryl esters in the rat |
| title_short | Metabolism of doubly-labeled chylomicron cholesteryl esters in the rat |
| title_sort | metabolism of doubly labeled chylomicron cholesteryl esters in the rat |
| topic | cholesteryl esters doubly-labeled in chylomicrons rat plasma clearance hepatic uptake |
| url | http://www.sciencedirect.com/science/article/pii/S0022227520401476 |
| work_keys_str_mv | AT stevenhquarfordt metabolismofdoublylabeledchylomicroncholesterylestersintherat AT dewittsgoodman metabolismofdoublylabeledchylomicroncholesterylestersintherat |