Effect of dietary magnesium deficiency with/without cholesterol supplementation on phospholipid content in liver, plasma and erythrocytes of rabbits.

The effect of magnesium deficiency with/without supplementary cholesterol on phospholipid content in liver, plasma and erythrocytes was investigated in New Zealand White male rabbits. After the rabbits had been fed a low magnesium and/or high cholesterol diet for seven weeks, the phospholipid content in liver, plasma and erythrocytes was measured. Dietary magnesium deficiency produced a marked elevation of total phospholipid and certain individual phospholipids in the rabbit liver. The elevation was accentuated by cholesterol supplementation. In the plasma, a low magnesium intake enhanced plasma phosphatidylcholine, phosphatidic acid, phosphatidylinositol, and sphingomyelin, but an activated conversion from phosphatidylethanolamine to phosphatidylcholine made the increase in phospholipid insignificant. On the other hand, a low magnesium intake restricted the increase in magnitude of phospholipid caused by cholesterol supplementation. In the erythrocytes, total phospholipid, phosphatidylcholine, phosphatidylethanolamine and phosphatidylserine were decreased by a low magnesium and/or a high cholesterol intake. We suggest that the increased contents of total phospholipid and/or certain individual phospholipids in the livers and plasma resulted from the enhanced synthesis of phospholipid in the liver by low magnesium intake. A decreased utilization of food by low magnesium diet limited the magnitude of plasma phospholipid increase produced by cholesterol supplementation.