Alterations in the Lipid Metabolism of Rat Aorta: Effects of Vitamin A DeficiencyGatica L.V. · Vega V.A. · Zirulnik F. · Oliveros L.B. · Gimenez M.S.
Department of Biochemistry and Biological Sciences, Faculty of Chemistry, Biochemistry and Pharmacy, National University of San Luis, San Luis, Argentina
Antioxidants are known to reduce cardiovascular disease by reducing the concentration of free radicals in the vessel wall and by preventing the oxidative modification of low-density lipoproteins. The prooxidative effect of a vitamin-A-deficient diet on the aorta has previously been demonstrated by us. In this study, the lipid metabolism in the aorta of rats fed on a vitamin-A-deficient diet was evaluated. Vitamin A deficiency induced a hypolipidemic effect (lower serum triglyceride and cholesterol levels) and a decreased serum paraoxonase 1/arylesterase activity. The concentrations of triglycerides, total cholesterol, free and esterified cholesterol, and phospholipids were increased in the aorta of vitamin-A-deficient rats. The phospholipid compositions showed an increase in phosphatidylcholine (PC), phosphatidylinositol plus phosphatidylserine and phosphatidylethanolamine, a decrease in sphingomyelin, and no change in phosphatidylglycerol. In the aorta, the increase in triglycerides was associated with an increased fatty acid synthesis and mRNA expression of diacylglycerol acyltransferase 1. The increased PC content was attributed to an increased synthesis, as measured by [methyl-14C]choline incorporation into PC and high CTP:phosphocholine cytidylyltransferase-α mRNA expression. The cholesterol synthesis, evaluated by [1-14C]acetate incorporated into cholesterol and mRNA expression of 3-hydroxy-3-methylglutaryl coenzyme A reductase, did not change. The lipoprotein lipase and lectin-like oxidized low-density lipoprotein receptor 1 mRNA expression levels increased in the aorta of vitamin-A-deficient animals. The incorporation of vitamin A into the diet of vitamin-A-deficient rats reverted all the changes observed. These results indicate that a vitamin-A-deficient diet,in addition to having a prooxidative effect, alters the aorta lipid metabolism.
© 2006 S. Karger AG, Basel
Received: November 24, 2005
Accepted after revision: August 5, 2006
Published online: October 13, 2006
Number of Print Pages : 9
Number of Figures : 3, Number of Tables : 3, Number of References : 42
Journal of Vascular Research (Incorporating 'International Journal of Microcirculation')
Vol. 43, No. 6, Year 2006 (Cover Date: November 2006)
Journal Editor: Pohl, U. (Munich)
ISSN: 1018–1172 (print), 1423–0135 (Online)
For additional information: http://www.karger.com/JVR