Iron-catalyzed lipid peroxidation in aortic cells in vitro: protective effect of extracellular magnesium

详细信息    查看全文

• 作者：Kostellow ; Adele B. ; Morrill ; Gene A.
• 关键词：Lipid peroxidation ; Magnesium ; Iron ; Glutathione ; Aortic cells ; Membrane lipids
• 刊名：Atherosclerosis
• 出版年：2004
• 出版时间：July, 2004
• 年：2004
• 卷：175
• 期：1
• 页码：15-22
• 全文大小：249 K

文摘

Low serum Mg²⁺ has been associated with an increased incidence of cardiovascular pathology in human populations. We investigated the effect of extracellular Mg²⁺ on Fe-catalyzed lipid peroxidation in rat aortic segments and in human aortic smooth muscle cells. Products of phospholipid oxidation [malonaldehyde (MDA) and 4-hydroxyalkenals (4-HA)], loss of fatty acyl double bonds (by proton-NMR) and glutathione levels indicated that exogenous ferric ions were several-fold more effective than ferrous ions in causing lipid peroxidation. Increased peroxidation was detectable at <1.0μM Fe³⁺. Exogenous ferric iron-ionophore, 8-hydroxyquinoline, did not increase peroxidation by ferric ion, suggesting that Fe-catalyzed lipid peroxidation occurred at the cell surface. As ionized serum [Mg²⁺]b>ob> was lowered from the physiological (0.7–0.96mM) into the pathophysiological range (0.3–0.5mM) in Fe³⁺-containing medium, MDA/4-HA levels increased two to three-fold, with a concomitant loss of fatty acyl double bonds and decreased extracellular glutathione. Conversely, MDA/4-HA decreased as ionized Mg²⁺ was increased, accompanied by a rise in extracellular glutathione. The results indicate that Mg²⁺ protects aortic cell plasma membranes from ferric iron-catalyzed lipid peroxidation and that this is a contributing factor in the protective action of ionized Mg²⁺ on the cardiovascular system.