+ 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 LinkedInFollow on LinkedIn

+ Translate

Dietary iron overload and induced lipid peroxidation are associated with impaired plasma lipid transport and hepatic sterol metabolism in rats

Dietary iron overload and induced lipid peroxidation are associated with impaired plasma lipid transport and hepatic sterol metabolism in rats

Hepatology 29(6): 1809-1817

Although hemochromatosis is characterized by dramatic morphological and functional alterations in the liver, little is known about the effects of an excess of iron on lipid metabolism. Therefore, we determined the effect of chronic iron overload on plasma lipid profile and lipoprotein composition, as well as on hepatic cholesterol metabolism and biliary sterol output. Rats administered a diet enriched with 3% iron carbonyl for 12 weeks displayed a 30-fold increase in iron (P <.0001) and a 5-fold rise in malondialdehyde (P <.001) in the liver. When compared with pair-fed controls, iron-overload rats showed a significant increase in triglycerides (P <.005), free cholesterol (P <.006), cholesteryl ester (P <.007), and high-density lipoprotein (HDL)-cholesterol (P <. 003). Triglyceride and cholesteryl ester enrichment, protein depletion, size increase, and apolipoprotein composition alterations characterized the very low density lipoprotein (VLDL) and HDL particles of iron-overload rats. Assessment of the activity of intracellular key enzymes for cholesterol homeostasis in these rats disclosed a reduction in 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase (66%, P <.005) and cholesterol 7alpha-hydroxylase (58%, P <.0004) with an increment of acyl-CoA: cholesterol acyltransferase (62%, P <.002). The lack of optimal enzymatic activity may be a result of marked membrane lipid peroxidation that brings about fluidity drop (P <.029) in microsomes of iron-overload rats (5.00 +/- 0.013) versus controls (8.20 +/- 0. 03), reflected by polarization. A decline of the pool size of cholesterol and bile acids was noted in iron-overload rats during a 6-hour bile drainage. Our results show that experimental iron overload causes marked perturbations in plasma lipid transport and hepatobiliary sterol metabolism. Given the positive correlation of malondialdehyde with most of the altered parameters, iron-catalyzed lipid peroxidation may well be one of the involved mechanisms.

(PDF emailed within 0-6 h: $19.90)

Accession: 010459957

Download citation: RISBibTeXText

PMID: 10347124

DOI: 10.1002/hep.510290612

Related references

Effects of vitamin E deficiency on hepatic mitochondrial lipid peroxidation and oxidative metabolism in rats with chronic dietary iron overload. Hepatology 9(3): 398-404, 1989

Hepatic mitochondrial oxidative metabolism and lipid peroxidation in experimental hexachlorobenzene-induced porphyria with dietary carbonyl iron overload. Hepatology 9(5): 686-692, 1989

Hepatic lipid peroxidation in vivo in rats with chronic dietary iron overload is dependent on hepatic iron concentration. Transactions of the Association of American Physicians 96: 146-154, 1983

Effects of glutathione gsh depletion on hepatic lipid peroxidation in rats with dietary iron overload. Hepatology: 1045, 1987

Dietary iron overload causes lipid peroxidation and alters liver cholesterol metabolism in rats. FASEB Journal 12(5): A1007, March 20, 1998

Effects of alpha-tocopherol and beta-carotene on hepatic lipid peroxidation and blood lipids in rats with dietary iron overload. Nutrition and Cancer 25(2): 119-128, 1996

Lipid peroxidation and alteration in calcium transport in mitochondria in the experimental hepatic iron overload. Journal of Hepatology 3: S68, 1986

Hepatic lipid peroxidation in vivo in rats with chronic iron overload. Journal of Clinical Investigation 71(3): 429-439, 1983

Dietary lipid and iron status modulate lipid peroxidation in rats with induced adjuvant arthritis. Journal of Nutrition 125(7): 1930-1937, 1995

Dose-responsive alteration in hepatic lipid peroxidation and retinol metabolism with increasing dietary beta-carotene in iron deficient rats. International Journal for Vitamin and Nutrition Research. Internationale Zeitschrift für Vitamin- und Ernahrungsforschung. Journal International de Vitaminologie et de Nutrition 72(5): 321-328, 2002

Effect of dietary iron overload on lipid peroxidation, prostaglandin synthesis and lymphocyte proliferation in young and old rats. Journal of Nutrition 120(3): 280-289, 1990

Effect of dietary iron overload in young and old rats on lipid peroxidation prostaglandin synthesis and lymphocyte proliferation. Federation Proceedings 46(4): 1161, 1987

Effects of dietary soybean lecithin on plasma lipid transport and hepatic cholesterol metabolism in rats. Journal of nutritional biochemistry 14(1): 40-48, 2003

Plasma antioxidants are strongly affected by iron-induced lipid peroxidation in rats subjected to physical exercise and different dietary fats. Biofactors 8(1-2): 119-127, 1998

Effect of dietary iron overload on plasma total antioxidant capacity and hepatic lipid peroxides in chickens. Journal of Dairy Science 84(Supplement 1): 133, 2001