Endotoxin-induced alterations of lipid and fatty acid compositions in rat liver peroxisomes.
The structure/function of peroxisomal lipids in rat liver treated with a sublethal dose of endotoxin, a lipopolysaccharide (LPS), was investigated. Peroxisomes isolated from LPS-treated rat liver had remarkable alterations in lipid content compared with saline treated control liver peroxisomes. Cholesterol and phospholipids (PL) decreased significantly by 28.7% and 50.8%, respectively, leading to the change in the ratio of cholesterol/phospholipids (control 0.081 versus LPS 0.118, P < 0.001). A quantitative analysis from LPS-treated rat liver peroxisomes showed a general decrease in all classes of PL. No such alterations were observed in lipid content of other subcellular organelles. The peroxisomal fatty acid composition in LPS-treated animals was also altered. An analysis of fatty acid composition in PL and phosphatidylcholine from LPS-treated peroxisomes showed an increase in arachidonic acid (C20:4) and docosahexaenoic acid (C22:6). Very long chain (VLC) fatty acids (> C22:0) were also found increased in all classes of lipids in LPS-treated peroxisomes. Gadolinium chloride (GAD) mediated inactivation of Kupffer cells (KC) normalized cholesterol/PL ratio in LPS-treated peroxisomes. Collectively, the results indicate that the peroxisome metabolism of lipids and fatty acids is specifically altered in endotoxin-treated rat liver and at least part of the alterations may be mediated by factors released by KC.
Khan
M
M
Department of Pediatrics, Medical University of South Carolina, Charleston 29425, USA.
Contreras
M
M
Singh
I
I
D000818:Animals; D004731:Endotoxins / Q000494:pharmacology*; D005227:Fatty Acids / Q000737:chemistry* / Q000378:metabolism; D050356:Lipid Metabolism; D008055:Lipids / Q000737:chemistry*; D008099:Liver / Q000737:chemistry* / Q000648:ultrastructure; D020675:Peroxisomes / Q000737:chemistry*; D051381:Rats; D017207:Rats, Sprague-Dawley; D012486:Salmonella typhimurium / Q000378:metabolism; D013347:Subcellular Fractions / Q000737:chemistry
D004731:Endotoxins; D005227:Fatty Acids; D008055:Lipids