Levels of polyunsaturated fatty acids in tissues from zinc-deficient rats fed a linseed oil diet.
The effect of zinc deficiency on the levels of n-6 and n-3 polyunsaturated fatty acids (PUFA) in lipids from tissues of rats fed a diet containing linseed oil was investigated. Rats were fed either a control diet (25 mg Zn/kg) or a zinc-deficient diet (0.8 mg Zn/kg) for 10 d. To avoid energy and nutrient deficiency, 11.6 g of diet per day was administered by gastric tube. At the end of the experiment, rats fed the zinc-deficient diet had drastically reduced plasma zinc concentration and alkaline phosphatase activity consistent with severe zinc deficiency in these rats. Zinc-deficient rats had higher levels of n-3 PUFA, in particular eicosapentaenoic acid (EPA), and lower levels of n-6 PUFA, in particular linoleic acid, in liver and plasma phosphatidylcholine (PC) and in erythrocyte membrane total lipids than did control rats. By contrast, the levels of n-3 PUFA in PC from testes and heart, and in phosphatidylethanolamine (PE) from liver, testes and heart, were only slightly different between zinc-deficient and control rats. The study suggests that desaturation of alpha-linolenic acid is not inhibited by zinc deficiency, and that in zinc-deficient rats, n-3 PUFA preferentially incorporated into phospholipids at the expense of n-6 PUFA, especially EPA into PC. The study also shows that the effect of zinc deficiency on PUFA levels is different for PC and PE in rat tissues.
Eder
K
K
Institut für Ernährungsphysiologie, Technische Universität München, Freising, Germany.
Kirchgessner
M
M
D000818:Animals; D004042:Dietary Fats, Unsaturated / Q000008:administration & dosage*; D005231:Fatty Acids, Unsaturated / Q000032:analysis; D008043:Linseed Oil / Q000008:administration & dosage; D050356:Lipid Metabolism; D008099:Liver / Q000378:metabolism* / Q000473:pathology; D008297:Male; D051381:Rats; D017207:Rats, Sprague-Dawley; D015032:Zinc / Q000172:deficiency*
D004042:Dietary Fats, Unsaturated; D005231:Fatty Acids, Unsaturated; D008043:Linseed Oil; D015032:Zinc