Oxidative modification of triglyceride‐rich lipoproteins in hypertriglyceridemic rats following magnesium deficiency

Gueux, Elyett; Cubizolles, Christine; Bussière, Laurence; Mazur, Andrzej; Rayssiguier, Yves

doi:10.1007/bf02536092

Cited by 17 publications

(1 citation statement)

References 19 publications

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“…At the present moment, pathologies as common as diabetes, hypertension and dyslipidaemia are associated with an altered metabolism of magnesium (1)(2)(3), and this divalent cation is even being considered as a potential tool in the prevention or co-adjuvant treatment of ventricular arrhythmias, coronary heart disease and cirrhosis of the liver (4-6), among others. Of the total magnesium body content, approximately 52% is found in bone, 46% in skeletal muscle and 2% in extracellular fluids (7).…”

Section: Introductionmentioning

confidence: 99%

Intracellular magnesium: transport and regulation in epithelial secretory cells

Yago

Mañas²,

Singh³

2000

Front Biosci

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ABSTRACT] i from magfura-2-loaded acini and acinar cells and Mg 2+ content in effluent samples from perfused pancreatic segments, respectively, confirm that secretagogues such as acetylcholine (ACh) and cholecystokinin-octapeptide (CCK-8) can evoke marked and significant extrusion of Mg 2+ which is closely associated with the mobilization of intracellular calcium. These effects may be modulated by different mediators including cAMP, Protein Kinase C and nitric oxide/cGMP. This reduction in [Mg 2+ ] i seems to be a prerequisite for optimal generation and maintenance of the calcium signal and subsequently, the secretion of enzymes, since an increase in extracellular Mg

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Section: Introductionmentioning

confidence: 99%

Intracellular magnesium: transport and regulation in epithelial secretory cells

Yago

Mañas²,

Singh³

2000

Front Biosci

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Atherogenic Lipid Fractions are Related to Free Magnesium Ion Status

Haenni

Öhrwall

Lithell

1997

Magnesium: Current Status and New Developments

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Consequences of treatment with dexamethasone in rats on the susceptibility of total plasma and isolated lipoprotein fractions to copper oxidation

Belkebir-Mesbah

Bonnefont‐Rousselot

Frey-Fressart

et al. 1999

Endocr

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According to the oxidative hypothesis of atherosclerosis, a hyperoxidizability of lipoproteins could favor the development of the atherosclerotic process. Besides, it has been recently reported that models of elevated very-low-density-lipoprotein (VLDL) levels in rats resulted in an increased susceptibility of these VLDL to oxidation. Treatment with dexamethasone classically induces an increase in plasma VLDL concentration. The aim of our study was thus to assess the effects of a treatment with dexamethasone in rats on the susceptibility to copper oxidation, both on total plasma and on isolated lipoproteins. Male Sprague-Dawley rats aged three months were treated with a daily intraperitoneal injection of dexamethasone (1.5 mg per kg) for five days (DEX group), whereas control rats were fed ad libitum (AL group). In order to take into account the decrease of food intake induced by dexamethasone treatment, a group of pair-fed rats was constituted (PF group). These rats had the same food intake as rats of the DEX group and were treated with a daily isovolumic intraperitoneal injection of NaCl for 5 d. After 5 d treatment, rats were fasted overnight, then killed, and blood was collected on EDTA. Low-density lipoproteins (VLDL + LDL) and high-density lipoproteins (HDL) were isolated by ultracentrifugation. A copper oxidation was conducted both on total plasma and on isolated lipoproteins. As expected, after treatment with dexamethasone, plasma exhibited increased triglyceride and glucose levels. Similarly, VLDL + LDL of rats from the DEX group were enriched with triglycerides, when compared with VLDL + LDL of the other two groups of rats. Our major finding was a marked increase in the susceptibility of total plasma of the DEX group to copper oxidation, in comparison with the other two groups of rats. This oxidizability was assessed by the maximal level of oxidation products absorbing at 234 nm and classically considered to be conjugated dienes (7.46+/-0.70 micromol L(-1) in the DEX group vs. 3.36+/-0.40 and 2.05+/-0.60 micromol L(-1) in the AL and PF groups, respectively). Nevertheless, this higher oxidizability was not observed in the isolated lipoprotein fractions, as shown by the formation of lipid peroxidation products such as conjugated dienes, thiobarbituric-acid reactive substances, hydroperoxides, 7-ketocholesterol, and dienals. This is not in agreement with other models of hypertriglyceridemia that have been reported to induce a hyperoxidizability of lipoproteins in rats. Our results led us to hypothesize that other plasma components such as proteins could be involved in this susceptibility to oxidation. Indeed, the severe protein catabolism induced by dexamethasone treatment could support this hypothesis, by forming protein components that are more susceptible to oxidation, as shown by an increased carbonyl formation upon plasma copper oxidation.

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Oxidative modification of triglyceride‐rich lipoproteins in hypertriglyceridemic rats following magnesium deficiency

Cited by 17 publications

References 19 publications

Intracellular magnesium: transport and regulation in epithelial secretory cells

Intracellular magnesium: transport and regulation in epithelial secretory cells

Atherogenic Lipid Fractions are Related to Free Magnesium Ion Status

Consequences of treatment with dexamethasone in rats on the susceptibility of total plasma and isolated lipoprotein fractions to copper oxidation

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