Plasma very low density lipoproteins from male rats fed casein or soybean protein diets: a comparison of fatty acid composition and influence on prostanoid production.
In studies with male rats fed for 4 wk semipurified diets containing olive oil and casein or soybean protein, protein-dependent effects were observed in the fatty acid composition of the VLDL lipids, especially with regard to the pattern of polyunsaturated fatty acids. Compared with VLDL from rats fed soybean protein diet (S-VLDL), VLDL from casein-fed rats (C-VLDL) contained a greater level of oleic acid, and a reduced level of linoleic acid and arachidonic acid, in the phosphatidylcholine fraction. The proportion of 5,8,11-eicosatrienoic acid, 20:3 (n-9), varied among the different lipid classes. The highest concentration of this fatty acid (13% by weight of total fatty acids) was observed in the phosphatidylinositol fraction of C-VLDL. The level of linoleic acid was approximately halved in the triacylglycerol and cholesteryl ester fractions of C-VLDL compared with S-VLDL. When mouse peritoneal macrophages were incubated with different concentrations of S-VLDL, a saturable accumulation of 6-keto-prostaglandin F1 alpha (6-keto-PGF1 alpha) and thromboxane B2 (TXB2) was observed in the cell medium. In contrast, very low levels of 6-keto-PGF1 alpha and TXB2 were observed in the cell medium of macrophages incubated with C-VLDL at different lipoprotein concentrations, suggesting that the composition of VLDL may play an important role in relation to cellular prostanoid metabolism.
Department of Medical and Physiological Chemistry, University of Uppsala, Sweden.
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Sjöblom
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Eklund
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L
Humble
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Menschik-Lundin
A M
AM
Ostlund-Lindqvist
D015121:6-Ketoprostaglandin F1 alpha / Q000096:biosynthesis*; D000818:Animals; D002364:Caseins / Q000008:administration & dosage*; D002478:Cells, Cultured; D004044:Dietary Proteins / Q000008:administration & dosage*; D005227:Fatty Acids / Q000737:chemistry*; D008079:Lipoproteins, VLDL / Q000097:blood* / Q000737:chemistry / Q000502:physiology; D008264:Macrophages / Q000378:metabolism / Q000648:ultrastructure; D008297:Male; D051379:Mice; D014674:Plant Proteins, Dietary / Q000008:administration & dosage*; D051381:Rats; D011919:Rats, Inbred Strains; D030262:Soybean Proteins; D013025:Glycine max / Q000737:chemistry; D013929:Thromboxane B2 / Q000096:biosynthesis*
D002364:Caseins; D004044:Dietary Proteins; D005227:Fatty Acids; D008079:Lipoproteins, VLDL; D014674:Plant Proteins, Dietary; D030262:Soybean Proteins; D013929:Thromboxane B2; D015121:6-Ketoprostaglandin F1 alpha