Inverse modifications of heart and liver alpha-tocopherol status by various dietary n-6/n-3 polyunsaturated fatty acid ratios.
The effect of dietary n-6/n-3 fatty acid ratio on alpha-tocopherol homeostasis was investigated in rats. Animals were fed diets containing fat (17% w/w) in which the n-6/n-3 ratio varied from 50 to 0.8. This was achieved by combining corn oil, fish oil, and lard. The polyunsaturated to saturated ratio and total alpha-tocopherol remained constant in all diets. Results showed that enrichment of n-3 polyunsaturated fatty acids in the diet, even at a low amount (3.9% w/w), resulted in a dramatic reduction of blood alpha-tocopherol concentration, which, in fact, is the result of a decrease in plasma lipids, since the alpha-tocopherol to total lipids ratio was not significantly altered. The most striking effect observed was a considerable alpha-tocopherol enrichment (x 4) of the heart as its membranes became enriched with n-3 polyunsaturated fatty acids. This process appeared even with a low amount of fish oil (3.9% w/w) added to the diet. Accordingly, a strong positive correlation was found between heart alpha-tocopherol and docosahexaenoic acid (r = 0.86) or docosahexaenoic acid plus eicosapentaenoic acid levels (r = 0.84). Conversely, the liver alpha-tocopherol level dropped dramatically when n-3 polyunsaturated fatty acids were gradually added to the diet. It is concluded that fish oil intake dramatically alters the alpha-tocopherol homeostasis in rats.
Chautan
M
M
Institut National de la Santé et de la Recherche Médicale, U130, Marseille, France.
Calaf
R
R
Léonardi
J
J
Charbonnier
M
M
Andre
M
M
Portugal
H
H
Pauli
A M
AM
Lafont
H
H
Nalbone
G
G
D000818:Animals; D004042:Dietary Fats, Unsaturated / Q000008:administration & dosage*; D006706:Homeostasis; D008055:Lipids / Q000097:blood; D008099:Liver / Q000378:metabolism*; D008297:Male; D009206:Myocardium / Q000378:metabolism*; D051381:Rats; D011919:Rats, Inbred Strains; D014810:Vitamin E / Q000097:blood / Q000378:metabolism*
D004042:Dietary Fats, Unsaturated; D008055:Lipids; D014810:Vitamin E