Magnesium fortification of drinking water suppresses atherogenesis in maleLDL-receptor-deficient mice

Magnesium, an important cofactor of more than 300 enzymes, has previously b een found to modulate blood lipid levels, atherogenesis and atherosclerosis in rabbits, when added to their diet. The aim of this study was to examine whether magnesium fortification of drinking water, without a change in die t content, can affect atherogenesis. The study included six groups of LDL-r eceptor-deficient mice. The mice received either distilled water or water c ontaining 50 g of magnesium sulfate per liter. In the first (12 weeks) and second (6 weeks) stages of the experiment, the mice received low- and high- cholesterol diets, respectively. At the end of each stage, blood was drawn for the determination of plasma magnesium, calcium and lipid levels. In add ition, the extent of atherosclerosis was determined at the aortic sinus. In both males and females, magnesium fortification was associated with higher levels of plasma magnesium (50 and 37% increase, respectively), without an y differences in plasma calcium content. The extent of atherosclerosis at t he aortic sinus in the male mice that received high levels of magnesium was a third of that of the male mice that received distilled water. However, t hese differences were not found in the female groups. Surprisingly, the fem ale mice that received water fortified with magnesium had higher levels of cholesterol after stage 2, whereas no differences regarding plasma lipid le vels were found among the male mice. These results confirm that magnesium f ortification of drinking water is capable of inhibiting atherogenesis in ma le LDL-receptor-deficient mice. The mechanisms of action are yet to be disc overed, and are probably not related to diminished lipid excretion, but pos sibly to the prevention of calcium influx into vascular smooth muscle cells , elevated antioxidative capacity, or other yet undetermined mechanisms. Co pyright (C) 2000 S. Karger AG, Basel.