Movement of lipolytic products to mitochondria in brown adipose tissue of young rats: an electron microscope study

Lipolysis occurred and lamellar structures with a periodicity of 40 A developed in glutaraldehyde-fixed brown adipose tissue of suckling rats when the tissue was incubated at 25 degrees C. The lamellar structures were found in capillaries, associated with chylomicrons, in intracellular channels of c...

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Main Authors: E J Blanchette-Mackie, R O Scow
Format: Article
Language:English
Published: Elsevier 1983-03-01
Series:Journal of Lipid Research
Online Access:http://www.sciencedirect.com/science/article/pii/S002222752037992X
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author E J Blanchette-Mackie
R O Scow
author_facet E J Blanchette-Mackie
R O Scow
author_sort E J Blanchette-Mackie
collection DOAJ
description Lipolysis occurred and lamellar structures with a periodicity of 40 A developed in glutaraldehyde-fixed brown adipose tissue of suckling rats when the tissue was incubated at 25 degrees C. The lamellar structures were found in capillaries, associated with chylomicrons, in intracellular channels of capillary endothelium, in extracellular space, and in channels near lipid droplets in adipocytes in tissue of fed rats injected intravenously with chylomicrons. They were also found in channels near mitochondria and inside mitochondria in adipocytes in incubated-fixed tissue of rats exposed to 4 degrees C for 2 hr or unsuckled overnight. In addition, aqueous spaces developed adjacent to lipid droplets in incubated tissue of cold-exposed and unsuckled rats. Development of lamellar structures under conditions causing lipolysis and accumulation of fatty acids in fixed tissue indicated the lamellae were composed primarily of fatty acids. We conclude that fatty acids formed by lipolysis of chylomicrons in tissue from fed rats accumulated in a continuum of the outer leaflets of cell membranes extending from capillary lumen to lipid droplets of adipocytes, and fatty acids formed by lipolysis of intracellular lipid in tissue from cold-exposed or unsuckled rats accumulated mostly in a continuum extending from lipid droplets to the interior of mitochondria. When fatty acids overcrowded the continuum in fixed tissue, they formed lamellar extensions of the continuum at different sites along its course through the tissue.
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spelling doaj.art-55f198f6e1ac4a6eae9c0f044778b3432022-12-21T23:19:15ZengElsevierJournal of Lipid Research0022-22751983-03-01243229244Movement of lipolytic products to mitochondria in brown adipose tissue of young rats: an electron microscope studyE J Blanchette-MackieR O ScowLipolysis occurred and lamellar structures with a periodicity of 40 A developed in glutaraldehyde-fixed brown adipose tissue of suckling rats when the tissue was incubated at 25 degrees C. The lamellar structures were found in capillaries, associated with chylomicrons, in intracellular channels of capillary endothelium, in extracellular space, and in channels near lipid droplets in adipocytes in tissue of fed rats injected intravenously with chylomicrons. They were also found in channels near mitochondria and inside mitochondria in adipocytes in incubated-fixed tissue of rats exposed to 4 degrees C for 2 hr or unsuckled overnight. In addition, aqueous spaces developed adjacent to lipid droplets in incubated tissue of cold-exposed and unsuckled rats. Development of lamellar structures under conditions causing lipolysis and accumulation of fatty acids in fixed tissue indicated the lamellae were composed primarily of fatty acids. We conclude that fatty acids formed by lipolysis of chylomicrons in tissue from fed rats accumulated in a continuum of the outer leaflets of cell membranes extending from capillary lumen to lipid droplets of adipocytes, and fatty acids formed by lipolysis of intracellular lipid in tissue from cold-exposed or unsuckled rats accumulated mostly in a continuum extending from lipid droplets to the interior of mitochondria. When fatty acids overcrowded the continuum in fixed tissue, they formed lamellar extensions of the continuum at different sites along its course through the tissue.http://www.sciencedirect.com/science/article/pii/S002222752037992X
spellingShingle E J Blanchette-Mackie
R O Scow
Movement of lipolytic products to mitochondria in brown adipose tissue of young rats: an electron microscope study
Journal of Lipid Research
title Movement of lipolytic products to mitochondria in brown adipose tissue of young rats: an electron microscope study
title_full Movement of lipolytic products to mitochondria in brown adipose tissue of young rats: an electron microscope study
title_fullStr Movement of lipolytic products to mitochondria in brown adipose tissue of young rats: an electron microscope study
title_full_unstemmed Movement of lipolytic products to mitochondria in brown adipose tissue of young rats: an electron microscope study
title_short Movement of lipolytic products to mitochondria in brown adipose tissue of young rats: an electron microscope study
title_sort movement of lipolytic products to mitochondria in brown adipose tissue of young rats an electron microscope study
url http://www.sciencedirect.com/science/article/pii/S002222752037992X
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AT roscow movementoflipolyticproductstomitochondriainbrownadiposetissueofyoungratsanelectronmicroscopestudy