+ Site Statistics
+ Search Articles
+ Subscribe to Site Feeds
EurekaMag Most Shared ContentMost Shared
EurekaMag PDF Full Text ContentPDF Full Text
+ PDF Full Text
Request PDF Full TextRequest PDF Full Text
+ Follow Us
Follow on FacebookFollow on Facebook
Follow on TwitterFollow on Twitter
Follow on Google+Follow on Google+
Follow on LinkedInFollow on LinkedIn

+ Translate

Effect of endotoxin on cholesterol biosynthesis and distribution in serum lipoproteins in Syrian hamsters

Journal of Lipid Research 34(12): 2147-2158

Effect of endotoxin on cholesterol biosynthesis and distribution in serum lipoproteins in Syrian hamsters

Infection and inflammation increase serum triglyceride and cholesterol levels in rodents and rabbits. Endotoxin (LPS) has been used as a model of infection and its effects on triglyceride metabolism have been previously characterized. In the present study we demonstrate that both low (100 ng/100 g body weight) and high dose (100 micrograms/100 g body weight) LPS increase serum cholesterol levels in hamsters. The increase in serum cholesterol is first observed 16 h after LPS and persists for at least 24 h. This increase is primarily due to an increase in low density lipoprotein (LDL) cholesterol. High density lipoprotein (HDL) cholesterol levels decrease after LPS treatment. Both low and high dose LPS increase hepatic cholesterol synthesis (low dose 85%, high dose 205%) and total HMG-CoA reductase activity (low dose 2.97-fold, high dose 9.96-fold). However, the proportion of HMG-CoA reductase in the active form is reduced by LPS treatment. Additionally, the mass of HMG-CoA reductase protein in the liver, measured by Western blotting, is increased after LPS. Moreover, LPS increases hepatic HMG-CoA reductase mRNA levels (low dose 3.1-fold, high dose 14.2-fold). The increase in hepatic HMG-CoA reductase mRNA levels is first seen 4 h after LPS and persists for at least 24 h. In contrast, LPS had only minimal effects on hepatic LDL receptor protein and mRNA levels. These results suggest that LPS increases serum cholesterol levels by increasing hepatic cholesterol synthesis. LPS administration decreases apoE mRNA levels in the liver while having no effect on apoA-I mRNA levels. These results suggest that HMG-CoA reductase is a member of a group of hepatic proteins that are positively regulated by inflammatory stimuli (acute phase proteins) while apoE can be considered a negative acute phase protein in hamsters. It is possible that increases in hepatic HMG-CoA reductase provide cholesterol that allows for the increased production of lipoproteins and elevations in serum lipid levels that may be beneficial to the body's host defense.

(PDF 0-2 workdays service: $29.90)

Accession: 002355356

PMID: 8301233

Related references

Epiberberine reduces serum cholesterol in diet-induced dyslipidemia Syrian golden hamsters via network pathways involving cholesterol metabolism. European Journal of Pharmacology 774: 1-9, 2015

Effect of the cholesterol biosynthesis inhibitor AY-9944 on serum lipoproteins of rats, pigs and dogs. Proc Soc Exp Biol Med 122(4): 1223-1228, 1966

Endotoxin and cytokines increase hepatic messenger RNA levels and serum concentrations of apolipoprotein J (clusterin) in Syrian hamsters. Journal of Clinical Investigation 94(3): 1304-1309, 1994

Effect of trans-1,4-bis cyclohexane dihydrochloride , an inhibitor of cholesterol biosynthesis, on serum lipoproteins in rats, pigs and dog. CIRCULATION 30(4 Suppl 3): III-14-III-15, 1964

5 alpha-Cholest-8(14)-en-3 beta-ol-15-one, a potent inhibitor of sterol biosynthesis, lowers serum cholesterol and alters distributions of cholesterol in lipoproteins in baboons. Proceedings of the National Academy of Sciences of the United States of America 79(9): 3042-3046, 1982

Cholesterol biosynthesis studies, m Effect of 5- 3-methylvalerlc acid on cholesterol biosynthesis and serum liver cholesterol content in the dog. 1966

Normal values of selected biochemical indexes in the blood serum of syrian hamsters i. the level of total protein and the values of relative percentage of electrophoretic protein fractions in the blood serum of syrian hamsters. Zwierzeta Laboratoryjne 19(1-2): 89-96, 1982

Endotoxin and cytokines decrease serum levels and extra hepatic protein and mRNA levels of CETP in Syrian hamsters. FASEB Journal 10(3): A552, 1996

Ethanol-extracted soy protein isolate does not modulate serum cholesterol in golden Syrian hamsters: a model of postmenopausal hypercholesterolemia. Journal of Nutrition 131(2): 211-214, 2001

Effect of vitamin B6 on the distribution of labeled cholesterol in beta-lipoproteins of blood serum under experimental hypercholesterolemia. Voprosy Meditsinskoi Khimii 13(1): 3-5, 1967