MODERATE IRON-DEFICIENCY AND FATTY-ACID SHIFTING IN LIVER AND BRAIN OF RATS

Iron deficiency is one of the most common nutritional deficiency in ma n and animals. This study with rats examined the effect of moderate an d slight iron deficiency on the composition of fatty acids in the live r and brain, as organs which differently manifest dietary variations. For that purpose, weanling male rats were divided into ic en groups of 12 each. Three groups were fed diets containing suboptimal iron: 9, 1 3 and 18 mg/kg over a period 5 weeks. The study a;so induced three pai r-fed control groups and an dd libitum-fed control group, fed with 50 mg iron per kg diet. Haemoglobin concentration, haematocrit and iron c oncentration in serum and liver reflected the grading iron status well , and decreased significantly by week 5 in rats on the iron-deficient diets demonstrating that the moderate iron deficiency was well develop ed 5 weeks after the experiment started. The fatty acid composition of the total hepatic lipids was markedly influenced by dietary iron depl etion, which was strongest in rats supplied with 9 mg iron/kg diet. In addition the weight;;ain slightly affected the fatty acid content in the liver. Among the iron-deficient: induced alterations in fatty acid composition and fatty acid concentrations of liver, reduced levels of individual monoenoic fatty acids and increased levels of linoleic aci d (18 :2 n-6) and alpha-linolenic: acid (18 :3 n-3) were most importan t. The ratio between 20:4 (n-6) and 18:2 (n-6), which is indicative of impaired Delta-6 and Delta-5 desaturation was markedly depressed in r ats supplied with 9 mg iron/kg diet. In the brain less alterations in fatty acid composition were observed by iron depletion than in liver. The main effects were elevated 18:2 (n-6), and depressed 22:4 (n-6) pr oportions in all iron-deficient groups relative to the pair-fed contro l groups. All moderately iron-deficient rats had a significantly lower ratio bera een the (n-6) fatty acids 20:4 and 18:2 than their corresp onding pair-fed controls. Since fatty acids have important functions i n the organism, e.g. as structural components of biological membranes or as precursors for synthesis of eicosanoids, the relationship betwee n moderate or slight :ron deficiency and the fatty acid shifting in li ver and brain observed might possibly be oi physiological importance.