A lipoprotein-containing particle is transferred from the serum across the mammary epithelium into the milk of lactating mice
To investigate the role of low-density lipoprotein (LDL) in the delivery of cholesterol to the mammary gland during pregnancy and lactation, we examined the distribution of radioactivity from 125I-tyramine cellobiose-LDL injected into the tail vein of female mice at various stages of the reproductiv...
| Main Authors: | , , , , , |
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| Format: | Article |
| Language: | English |
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Elsevier
2001-05-01
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| Series: | Journal of Lipid Research |
| Subjects: | |
| Online Access: | http://www.sciencedirect.com/science/article/pii/S0022227520316308 |
| _version_ | 1818731619122413568 |
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| author | Jenifer Monks Patricia Uelmen Huey Linda Hanson Robert H. Eckel Margaret C. Neville Sean Gavigan |
| author_facet | Jenifer Monks Patricia Uelmen Huey Linda Hanson Robert H. Eckel Margaret C. Neville Sean Gavigan |
| author_sort | Jenifer Monks |
| collection | DOAJ |
| description | To investigate the role of low-density lipoprotein (LDL) in the delivery of cholesterol to the mammary gland during pregnancy and lactation, we examined the distribution of radioactivity from 125I-tyramine cellobiose-LDL injected into the tail vein of female mice at various stages of the reproductive cycle. Changes in the proportion of isotope taken up by the mammary gland largely reflected the increased weight of the gland in pregnancy and lactation. In addition, during lactation, radioactivity was found in the milk and was associated with a protein of the molecular weight of apoB-100. Quantitatively similar results were obtained with mice homozygous for disruption of the LDL receptor gene (LDLR null). Analysis of endogenous lipoproteins showed that the milk lipoprotein particles were denser than the corresponding serum lipoproteins and largely depleted of triglyceride and cholesterol. Using fluorescence microscopy we visualize the sorting of apoB protein from the LDL lipid phase at the basal surface of the mammary epithelial cell of both wild-type and LDLR-null mice. Our findings provide evidence that the mammary epithelium of the lactating mouse is able to take up LDL from the plasma by a non-LDLR-mediated process. An apoB-containing particle from which the cholesterol has been removed is transferred into milk.—Monks, J., P. U. Huey, L. Hanson, R. H. Eckel, M. C. Neville, and S. Gavigan. A lipoprotein-containing particle is transferred from the serum across the mammary epithelium into the milk of lactating mice. J. Lipid Res. 2001. 42: 686–696. |
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| id | doaj.art-78d0f95337024dfe9282bea83c9c696b |
| institution | Directory Open Access Journal |
| issn | 0022-2275 |
| language | English |
| last_indexed | 2024-12-17T23:20:33Z |
| publishDate | 2001-05-01 |
| publisher | Elsevier |
| record_format | Article |
| series | Journal of Lipid Research |
| spelling | doaj.art-78d0f95337024dfe9282bea83c9c696b2022-12-21T21:28:54ZengElsevierJournal of Lipid Research0022-22752001-05-01425686696A lipoprotein-containing particle is transferred from the serum across the mammary epithelium into the milk of lactating miceJenifer Monks0Patricia Uelmen Huey1Linda Hanson2Robert H. Eckel3Margaret C. Neville4Sean Gavigan5Department of Physiology and Biophysics, University of Colorado Health Sciences Center, Denver, CO 80262Department of Medicine, Division of Endocrinology, Metabolism and Diabetes, University of Colorado Health Sciences Center, Denver, CO 80262Department of Physiology and Biophysics, University of Colorado Health Sciences Center, Denver, CO 80262Department of Medicine, Division of Endocrinology, Metabolism and Diabetes, University of Colorado Health Sciences Center, Denver, CO 80262Department of Physiology and Biophysics, University of Colorado Health Sciences Center, Denver, CO 80262; Department of Physiology and Biophysics, University of Colorado Health Sciences Center, 4200 East Ninth Avenue, C-240 Denver CO 80262Department of Physiology and Biophysics, University of Colorado Health Sciences Center, Denver, CO 80262To investigate the role of low-density lipoprotein (LDL) in the delivery of cholesterol to the mammary gland during pregnancy and lactation, we examined the distribution of radioactivity from 125I-tyramine cellobiose-LDL injected into the tail vein of female mice at various stages of the reproductive cycle. Changes in the proportion of isotope taken up by the mammary gland largely reflected the increased weight of the gland in pregnancy and lactation. In addition, during lactation, radioactivity was found in the milk and was associated with a protein of the molecular weight of apoB-100. Quantitatively similar results were obtained with mice homozygous for disruption of the LDL receptor gene (LDLR null). Analysis of endogenous lipoproteins showed that the milk lipoprotein particles were denser than the corresponding serum lipoproteins and largely depleted of triglyceride and cholesterol. Using fluorescence microscopy we visualize the sorting of apoB protein from the LDL lipid phase at the basal surface of the mammary epithelial cell of both wild-type and LDLR-null mice. Our findings provide evidence that the mammary epithelium of the lactating mouse is able to take up LDL from the plasma by a non-LDLR-mediated process. An apoB-containing particle from which the cholesterol has been removed is transferred into milk.—Monks, J., P. U. Huey, L. Hanson, R. H. Eckel, M. C. Neville, and S. Gavigan. A lipoprotein-containing particle is transferred from the serum across the mammary epithelium into the milk of lactating mice. J. Lipid Res. 2001. 42: 686–696.http://www.sciencedirect.com/science/article/pii/S0022227520316308mammary glandcholesterolepitheliumLDLLDLR-null micetranscytosis |
| spellingShingle | Jenifer Monks Patricia Uelmen Huey Linda Hanson Robert H. Eckel Margaret C. Neville Sean Gavigan A lipoprotein-containing particle is transferred from the serum across the mammary epithelium into the milk of lactating mice Journal of Lipid Research mammary gland cholesterol epithelium LDL LDLR-null mice transcytosis |
| title | A lipoprotein-containing particle is transferred from the serum across the mammary epithelium into the milk of lactating mice |
| title_full | A lipoprotein-containing particle is transferred from the serum across the mammary epithelium into the milk of lactating mice |
| title_fullStr | A lipoprotein-containing particle is transferred from the serum across the mammary epithelium into the milk of lactating mice |
| title_full_unstemmed | A lipoprotein-containing particle is transferred from the serum across the mammary epithelium into the milk of lactating mice |
| title_short | A lipoprotein-containing particle is transferred from the serum across the mammary epithelium into the milk of lactating mice |
| title_sort | lipoprotein containing particle is transferred from the serum across the mammary epithelium into the milk of lactating mice |
| topic | mammary gland cholesterol epithelium LDL LDLR-null mice transcytosis |
| url | http://www.sciencedirect.com/science/article/pii/S0022227520316308 |
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