Electron microscopic and biochemical study of lipoprotein synthesis in the isolated perfused rat liver
The isolated perfused rat liver was used to study the 300-800 A electron-opaque bodies which had previously been described in the liver cell Golgi apparatus, smooth endoplasmic reticulum, and space of Disse.When the perfusion medium was enriched with linoleate, the number and electron opacity of the...
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| Format: | Article |
| Language: | English |
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Elsevier
1967-09-01
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| Series: | Journal of Lipid Research |
| Subjects: | |
| Online Access: | http://www.sciencedirect.com/science/article/pii/S0022227520389008 |
| _version_ | 1819315653237014528 |
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| author | Albert L. Jones Neil B. Ruderman M. Guillermo Herrera |
| author_facet | Albert L. Jones Neil B. Ruderman M. Guillermo Herrera |
| author_sort | Albert L. Jones |
| collection | DOAJ |
| description | The isolated perfused rat liver was used to study the 300-800 A electron-opaque bodies which had previously been described in the liver cell Golgi apparatus, smooth endoplasmic reticulum, and space of Disse.When the perfusion medium was enriched with linoleate, the number and electron opacity of these particles increased markedly. Sequential biopsies showed that they appeared first in the smooth surfaced terminal ends of the rough reticulum, the smooth endoplasmic reticulum proper, and the Golgi apparatus and later in the space of Disse. After 60 min of perfusion, particles of the same size and shape as those in the liver cells could be isolated in large numbers from the d < 1.006 fraction of the perfusate. Control livers perfused with an identical medium but without linoleate did not show these changes.Puromycin markedly depressed the production of 300-800 A particles by livers perfused with an oleate-rich medium; however, it did not interfere with the formation of large cytoplasmic droplets of neutral fat. In keeping with these findings, puromycin blocked the incorporation of oleate-14C into lipoprotein triglyceride isolated from the perfusate, but did not interfere with the appearance of the labeled fatty acid in tissue triglyceride. Puromycin also blocked the incorporation of leucine-3H into both tissue protein and perfusate lipoprotein. We concluded that the 300-800 A particles observed are, in all likelihood, very low density lipoproteins and that their formation is blocked by puromycin, presumably through interference with the synthesis of their apoprotein. |
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| format | Article |
| id | doaj.art-7b687e5947a540e5979966e7c08d455e |
| institution | Directory Open Access Journal |
| issn | 0022-2275 |
| language | English |
| last_indexed | 2024-12-24T10:03:31Z |
| publishDate | 1967-09-01 |
| publisher | Elsevier |
| record_format | Article |
| series | Journal of Lipid Research |
| spelling | doaj.art-7b687e5947a540e5979966e7c08d455e2022-12-21T17:00:55ZengElsevierJournal of Lipid Research0022-22751967-09-0185429446Electron microscopic and biochemical study of lipoprotein synthesis in the isolated perfused rat liverAlbert L. Jones0Neil B. Ruderman1M. Guillermo Herrera2Department of Anatomy and Elliott P. Joslin Research Laboratory, Department of Medicine, Harvard Medical School, Peter Bent Brigham Hospital and Diabetes Foundation, Inc., Boston, Massachusetts 02215; Department of Nutrition, Harvard School of Public Health, Boston, Massachusetts 02215; Peter Bent Brigham Hospital and Diabetes Foundation, Inc., Boston, Massachusetts 02215Department of Anatomy and Elliott P. Joslin Research Laboratory, Department of Medicine, Harvard Medical School, Peter Bent Brigham Hospital and Diabetes Foundation, Inc., Boston, Massachusetts 02215; Department of Nutrition, Harvard School of Public Health, Boston, Massachusetts 02215; Peter Bent Brigham Hospital and Diabetes Foundation, Inc., Boston, Massachusetts 02215Department of Anatomy and Elliott P. Joslin Research Laboratory, Department of Medicine, Harvard Medical School, Peter Bent Brigham Hospital and Diabetes Foundation, Inc., Boston, Massachusetts 02215; Department of Nutrition, Harvard School of Public Health, Boston, Massachusetts 02215; Peter Bent Brigham Hospital and Diabetes Foundation, Inc., Boston, Massachusetts 02215The isolated perfused rat liver was used to study the 300-800 A electron-opaque bodies which had previously been described in the liver cell Golgi apparatus, smooth endoplasmic reticulum, and space of Disse.When the perfusion medium was enriched with linoleate, the number and electron opacity of these particles increased markedly. Sequential biopsies showed that they appeared first in the smooth surfaced terminal ends of the rough reticulum, the smooth endoplasmic reticulum proper, and the Golgi apparatus and later in the space of Disse. After 60 min of perfusion, particles of the same size and shape as those in the liver cells could be isolated in large numbers from the d < 1.006 fraction of the perfusate. Control livers perfused with an identical medium but without linoleate did not show these changes.Puromycin markedly depressed the production of 300-800 A particles by livers perfused with an oleate-rich medium; however, it did not interfere with the formation of large cytoplasmic droplets of neutral fat. In keeping with these findings, puromycin blocked the incorporation of oleate-14C into lipoprotein triglyceride isolated from the perfusate, but did not interfere with the appearance of the labeled fatty acid in tissue triglyceride. Puromycin also blocked the incorporation of leucine-3H into both tissue protein and perfusate lipoprotein. We concluded that the 300-800 A particles observed are, in all likelihood, very low density lipoproteins and that their formation is blocked by puromycin, presumably through interference with the synthesis of their apoprotein.http://www.sciencedirect.com/science/article/pii/S0022227520389008ratperfused liverfatty acid-albuminelectron microscopyosmiophilic particlesvery low density lipoproteins |
| spellingShingle | Albert L. Jones Neil B. Ruderman M. Guillermo Herrera Electron microscopic and biochemical study of lipoprotein synthesis in the isolated perfused rat liver Journal of Lipid Research rat perfused liver fatty acid-albumin electron microscopy osmiophilic particles very low density lipoproteins |
| title | Electron microscopic and biochemical study of lipoprotein synthesis in the isolated perfused rat liver |
| title_full | Electron microscopic and biochemical study of lipoprotein synthesis in the isolated perfused rat liver |
| title_fullStr | Electron microscopic and biochemical study of lipoprotein synthesis in the isolated perfused rat liver |
| title_full_unstemmed | Electron microscopic and biochemical study of lipoprotein synthesis in the isolated perfused rat liver |
| title_short | Electron microscopic and biochemical study of lipoprotein synthesis in the isolated perfused rat liver |
| title_sort | electron microscopic and biochemical study of lipoprotein synthesis in the isolated perfused rat liver |
| topic | rat perfused liver fatty acid-albumin electron microscopy osmiophilic particles very low density lipoproteins |
| url | http://www.sciencedirect.com/science/article/pii/S0022227520389008 |
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