Dietary magnesium affects susceptibility of lipoproteins and tissues to peroxidation in rats.

Abstract

Magnesium (Mg)-deficient and control diets were pair-fed to weanling Wistar rats for 8 days. Plasma lipoproteins were separated into various density classes by sequential preparative ultracentrifugation. The extent of lipid peroxidation was measured in terms of thiobarbituric acid reactive substances in lipoproteins and tissue homogenates before or after iron-induced lipid peroxidation. Hyperlipemia in Mg-deficient rats was accompanied by increased oxidation of very-low-density lipoproteins and low-density lipoproteins. Moreover, very-low-density lipoproteins and high-density lipoproteins from Mg-deficient rats were more susceptible to oxidative damage following iron incubation. Mg deficiency increased lipid peroxidation in liver, heart and skeletal muscles. Their homogenates were more susceptible to in vitro peroxidation. Mg deficiency has been discussed as a possible contributory factor in the development of cardiovascular disease and was associated with tissue damage and membrane alteration. These results demonstrate for the first time that Mg affects the susceptibility of lipoproteins to peroxidation and suggest that the mechanism responsible for the pathological consequences of Mg deficiency may be mediated by lipid peroxidation products.

Intake of Potassium, Magnesium, Calcium, and Fiber and Risk of Stroke Among US Men

“…27 Also, there are reports that magnesium deficiency increases suscep- tibility of lipoproteins to peroxidation in rats. 28 Conversely, magnesium supplementation failed to reduce blood pressure in randomized trials among normotensive subjects, 7,29 and high-magnesium diets have been reported to increase rather than decrease the risk of stroke in hypertensive rats. 30 In a randomized trial in China, a multiple vitamin/mineral supplement containing 200 mg of magnesium reduced the risk of stroke among men, but this effect may have been due to 1 of the several other micronutrients included in the supplement.…”

Effects of exercise and training in hypoxia on antioxidant/pro-oxidant balance

“…Plasma MDA Concentrations of basal plasma MDA were determined as thiobarbituric-reactive substances by a modified method of Ohkawa et al (1979) as previously described (Rayssiguier et al, 1993). The pink chromogen was extracted with n-butanol (4 ml), and its absorbance was measured at 532 nm by spectrophotometry (Perkin Elmer Cetus, Norwalk, CT, USA).…”

Newer aspects of micronutrients in chronic disease: copper

“…Cu deficiency not only increases serum cholesterol but also increases the susceptibility of very-low-density lipoprotein (VLDL) and LDL to in v i m Cu-induced oxidation (Rayssiguier et al 1993). These workers also found increased thiobarbituric acid-reactive substances in heart and liver tissues from Cu-deficient rats while Nelson et al (1992) found increased aortic lipid peroxides (malondialdehyde equivalents) in rats fed on Cu-marginal and Cu-deficient diets, the latter increase being associated with depressed aortic CuZn-SOD activity.…”