No abstract

In view of the clinical importance of iron deficiency as well as the known role of iron in stearic acid desaturation, the effects of higher or lower iron intake on fatty acid composition of blood and liver in the rat were studied. Male Sprague-Dawley rats were fed purified diets that contained iron at 12, 27 or 237 mg/kg. After 12 wk the lipid and fatty acid composition of plasma, erythrocytes and liver was analyzed. Linoleic acid in plasma phospholipids and triacylglycerols was higher, but arachidonic acid was lower in the group fed 12 mg/kg iron than in the groups fed 27 or 237 mg/kg iron. Liver fatty acid and lipid composition was not different between groups. In the group fed 237 mg/kg iron, plasma cholesterol and triacylglycerols were 150%, erythrocyte cholesterol was 137% and erythrocyte phospholipids were 148% of levels in the rats fed 27 mg/kg iron. The fatty acid data suggest a mild impairment in essential fatty acid metabolism in moderately iron-deficient rats. The lipid data suggest a significant alteration in the total lipid content of plasma and erythrocytes of iron-supplemented rats.

Experiments were conducted to study the total lipid and fatty acid composition of liver, kidney, brain and heart of 7-wk-old male C57BL mice. Dietary copper deficiency was initiated at birth by feeding dams a purified diet containing 0.5 mg/kg copper. Offspring were fed the copper-deficient diet 4 wk postweaning. Control dams and offspring were fed the same diet but with added copper in the drinking water, 20 mg/L. Compared with controls the copper-deficient mice exhibited hepatomegaly, cardiac hypertrophy and a 4% reduction in brain weight as well as low ceruloplasmin activity (0.5% of control). Total phospholipid concentration in liver and kidney and total triacylglycerol concentration in kidney was lower in copper-deficient mice compared to concentrations measured in liver and kidney of control mice. The major change in essential fatty acid composition in the copper-deficient mice which was consistent between organs and lipid classes was a significantly lower proportion and absolute amount of dihomo-gamma-linolenic acid. Other changes in fatty acid composition were variable.

No abstract

The effects of magnesium deficiency on tissue levels of total lipids and fatty acids were evaluated. Sprague-Dawley rats were fed a magnesium-deficient diet for 14 wk with controls being pair-fed to the deficient rats. Compared to the controls, serum and 24-h urinary magnesium levels were markedly lower in the magnesium-deficient rats. Serum cholesterol and total phospholipids were significantly higher in the magnesium-deficient rats than in the controls. Edema and polycystic degeneration of the kidneys were present in the magnesium-deficient rats. Kidney total phospholipids and triacylglycerols were significantly lower in the magnesium-deficient rats than in the controls. The main change in tissue fatty acid composition in magnesium deficiency was the higher docosahexaenoic acid (22:6n-3) in serum, liver and aorta than in controls. The possible relationship of these findings to human alcoholism is discussed.