Measurement of human apolipoprotein B-48 and B-100 kinetics in triglyceride-rich lipoproteins using [5,5,5-2H3]leucine.
A primed-constant infusion of deuterated leucine was used in humans to determine the maximal level of enrichment at plateau of apolipoprotein (apo)B-48 and apoB-100 which are synthesized in the intestine and liver, respectively, and to compare the kinetics of these two proteins under identical condi...
| Main Authors: | , , , , , , |
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| Format: | Article |
| Language: | English |
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Elsevier
1992-06-01
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| Series: | Journal of Lipid Research |
| Online Access: | http://www.sciencedirect.com/science/article/pii/S0022227520415160 |
| _version_ | 1818590586524925952 |
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| author | AH Lichtenstein DL Hachey JS Millar JL Jenner L Booth J Ordovas EJ Schaefer |
| author_facet | AH Lichtenstein DL Hachey JS Millar JL Jenner L Booth J Ordovas EJ Schaefer |
| author_sort | AH Lichtenstein |
| collection | DOAJ |
| description | A primed-constant infusion of deuterated leucine was used in humans to determine the maximal level of enrichment at plateau of apolipoprotein (apo)B-48 and apoB-100 which are synthesized in the intestine and liver, respectively, and to compare the kinetics of these two proteins under identical conditions. Eight normal subjects (four post-menopausal females and four males) over the age of 40 were studied in the constantly fed state over a 20-h period by providing small hourly feedings of identical composition. [5,5,5-2H3]Leucine (10 mumol/kg body weight followed by 10 mumol/kg body weight per hour) was infused over 15 h intravenously. The enrichment of deuterated leucine in apoB-48 and apoB-100 triglyceride-rich lipoproteins isolated by ultracentrifugation (d less than 1.006 g/ml) was determined during the entire infusion period. The plateau level of enrichment in triglyceride-rich lipoprotein apoB-48 was 3.96 +/- 1.41 tracer/tracee ratio (%) which was 39.7% of the plasma leucine enrichment level. The plateau level of enrichment in triglyceride-rich lipoprotein apoB-100 was 7.23 +/- 1.17 tracer/tracee ratio (%) which was 72.5% of the plasma leucine enrichment level. Mean fractional secretion rates of triglyceride-rich lipoprotein apoB-48 and apoB-100 were 4.39 +/- 2.00 and 5.39 +/- 1.98 pools per day, respectively, with estimated residence times of 5.47 and 4.45 hours, respectively. The data indicate that in the fed state there is about a twofold difference in the plateau enrichment of an intestinally derived protein, as compared to one of hepatic origin, most likely attributable to differences in the enrichment of the intracellular leucine in the two organs.(ABSTRACT TRUNCATED AT 250 WORDS) |
| first_indexed | 2024-12-16T09:58:54Z |
| format | Article |
| id | doaj.art-2e31d0bce5c44d928a5e32d3fa60d873 |
| institution | Directory Open Access Journal |
| issn | 0022-2275 |
| language | English |
| last_indexed | 2024-12-16T09:58:54Z |
| publishDate | 1992-06-01 |
| publisher | Elsevier |
| record_format | Article |
| series | Journal of Lipid Research |
| spelling | doaj.art-2e31d0bce5c44d928a5e32d3fa60d8732022-12-21T22:35:50ZengElsevierJournal of Lipid Research0022-22751992-06-01336907914Measurement of human apolipoprotein B-48 and B-100 kinetics in triglyceride-rich lipoproteins using [5,5,5-2H3]leucine.AH Lichtenstein0DL Hachey1JS Millar2JL Jenner3L Booth4J Ordovas5EJ Schaefer6Lipid Metabolism Laboratory, USDA Human Nutrition Research Center on Aging, Tufts University, Boston, MA 02111.Lipid Metabolism Laboratory, USDA Human Nutrition Research Center on Aging, Tufts University, Boston, MA 02111.Lipid Metabolism Laboratory, USDA Human Nutrition Research Center on Aging, Tufts University, Boston, MA 02111.Lipid Metabolism Laboratory, USDA Human Nutrition Research Center on Aging, Tufts University, Boston, MA 02111.Lipid Metabolism Laboratory, USDA Human Nutrition Research Center on Aging, Tufts University, Boston, MA 02111.Lipid Metabolism Laboratory, USDA Human Nutrition Research Center on Aging, Tufts University, Boston, MA 02111.Lipid Metabolism Laboratory, USDA Human Nutrition Research Center on Aging, Tufts University, Boston, MA 02111.A primed-constant infusion of deuterated leucine was used in humans to determine the maximal level of enrichment at plateau of apolipoprotein (apo)B-48 and apoB-100 which are synthesized in the intestine and liver, respectively, and to compare the kinetics of these two proteins under identical conditions. Eight normal subjects (four post-menopausal females and four males) over the age of 40 were studied in the constantly fed state over a 20-h period by providing small hourly feedings of identical composition. [5,5,5-2H3]Leucine (10 mumol/kg body weight followed by 10 mumol/kg body weight per hour) was infused over 15 h intravenously. The enrichment of deuterated leucine in apoB-48 and apoB-100 triglyceride-rich lipoproteins isolated by ultracentrifugation (d less than 1.006 g/ml) was determined during the entire infusion period. The plateau level of enrichment in triglyceride-rich lipoprotein apoB-48 was 3.96 +/- 1.41 tracer/tracee ratio (%) which was 39.7% of the plasma leucine enrichment level. The plateau level of enrichment in triglyceride-rich lipoprotein apoB-100 was 7.23 +/- 1.17 tracer/tracee ratio (%) which was 72.5% of the plasma leucine enrichment level. Mean fractional secretion rates of triglyceride-rich lipoprotein apoB-48 and apoB-100 were 4.39 +/- 2.00 and 5.39 +/- 1.98 pools per day, respectively, with estimated residence times of 5.47 and 4.45 hours, respectively. The data indicate that in the fed state there is about a twofold difference in the plateau enrichment of an intestinally derived protein, as compared to one of hepatic origin, most likely attributable to differences in the enrichment of the intracellular leucine in the two organs.(ABSTRACT TRUNCATED AT 250 WORDS)http://www.sciencedirect.com/science/article/pii/S0022227520415160 |
| spellingShingle | AH Lichtenstein DL Hachey JS Millar JL Jenner L Booth J Ordovas EJ Schaefer Measurement of human apolipoprotein B-48 and B-100 kinetics in triglyceride-rich lipoproteins using [5,5,5-2H3]leucine. Journal of Lipid Research |
| title | Measurement of human apolipoprotein B-48 and B-100 kinetics in triglyceride-rich lipoproteins using [5,5,5-2H3]leucine. |
| title_full | Measurement of human apolipoprotein B-48 and B-100 kinetics in triglyceride-rich lipoproteins using [5,5,5-2H3]leucine. |
| title_fullStr | Measurement of human apolipoprotein B-48 and B-100 kinetics in triglyceride-rich lipoproteins using [5,5,5-2H3]leucine. |
| title_full_unstemmed | Measurement of human apolipoprotein B-48 and B-100 kinetics in triglyceride-rich lipoproteins using [5,5,5-2H3]leucine. |
| title_short | Measurement of human apolipoprotein B-48 and B-100 kinetics in triglyceride-rich lipoproteins using [5,5,5-2H3]leucine. |
| title_sort | measurement of human apolipoprotein b 48 and b 100 kinetics in triglyceride rich lipoproteins using 5 5 5 2h3 leucine |
| url | http://www.sciencedirect.com/science/article/pii/S0022227520415160 |
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