Please use this identifier to cite or link to this item: http://hdl.handle.net/2445/111307
Title: Lipoprotein lipase: cellular origin and functional distribution
Author: Camps, L.
Reina del Pozo, Manuel
Llobera i Sande, Miquel
Vilar Coma, Senen
Olivercrona, T.
Keywords: Lipoproteïnes
Lipases
Lipoproteins
Lipase
Issue Date: 1-Apr-1990
Publisher: American Physiological Society
Abstract: Lipoprotein lipase (LPL, E.C. 3.3.1.34) is the enzyme responsible for hydrolysis of triacylglycerols in plasma lipoproteins, making the fatty acids available for use by subjacent tissues. LPL is functional at the surface of endothelial cells, but it is not clear which cells synthesize the enzyme and what its distribution is within tissues and vessels. We have searched for specific cell expression of the LPL gene by in situ hybridization using a RNA probe and for the corresponding protein distribution by immunocytochemistry on cryosections of some LPL-producing tissues of guinea pigs. In white and brown adipose tissues, heart and skeletal muscle, and lactating mammary gland, there was positive hybridization for LPL mRNA over all members of the major cell types, indicating that mature and immature adipocytes, muscle cells, and mammary epithelial cells are main sources of LPL. In large vessels, LPL expression was detected in some smooth muscle cells in the media layer. There was no positive hybridization for LPL mRNA over endothelial cells in any of the tissues studied, but there was immunoreaction for LPL protein at endothelial surfaces of all blood vessels. In the kidney, there was strong immunofluorescence at the vascular endothelium, particularly in the glomeruli, but little or no LPL mRNA was detected in the surrounding cells. These observations suggest that in some tissues LPL is synthesized by parenchymal cells and spreads along the vascular mesh. Transfer to the vascular endothelium is, however, not the only route taken by LPL. In the mammary gland most of the enzyme protein appeared to be secreted, partly in association with milk fat droplets.
Note: Versió postprint del document publicat a: http://ajpcell.physiology.org/content/258/4/C673
It is part of: American Journal of Physiology, 1990, vol. 258, num. 4, p. 673-681
URI: http://hdl.handle.net/2445/111307
ISSN: 0002-9513
Appears in Collections:Articles publicats en revistes (Biologia Cel·lular, Fisiologia i Immunologia)
Articles publicats en revistes (Bioquímica i Biomedicina Molecular)

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