The effects of dietary oils on the fatty acid composition and osmotic fragility of rat erythrocytes.
The effects of dietary oils on the fatty acid composition and osmotic fragility of rat erythrocytes.
Year: 1994
Authors: M Kirchgebner, G I Stangl, A M Reichlmayr-Lais, K Elder.
Publication Name: Z. Emahrungswiss.
Publication Details: Volume 33; 146.
Abstract:
This research is a continuation of work reported by Stangl et al., (J. Anim. Physio. Anim. Nutr. 70:207, 1994) to examine the effects of dietary fatty acids on lipid membrane composition and function in animals. This study determined the effect of various dietary oils containing different proportions of saturated (SFA), monounsaturated (MUFA) and polyunsaturated n?6 and n?3 fatty acids (PUFA) on fatty acid composition and on the osmotic fragility of rat erythrocyte membranes. Following a 28 day control diet consisting of 10% (wt/wt) coconut oil and 0.4% safflower oil, 10 rats each were fed diets containing 5% and10%, by weight, olive oil (OO5 & OO10 ? 72% OL), safflower oil (SFO5 & SFO10 ? 78% LA), EPO (EPO5 & EPO 10 ? 9% GLA), FO (FO5 & FO10 ? 56% ALA), or salmon oil (SLO5 & SLO10 ? 30% EPA, DPA and DHA) for an additional 20 days. The results of this study support previous observations which indicated that the fatty acid composition of erythrocyte lipids can be modified by dietary fatty acids. SFA contents were slightly lower in the erythrocytes of rats fed oils high in MUFA (OO10) or PUFA (EPO10, FO5 & FO10). MUFA levels were the highest following the OO diets. This increase in MUFA was at the expense of SFA and n?6 PUFAs, was most pronounced with respect to OL and occured in a dose?dependent manner. Rats fed SFO, EPO or flaxseed oil had higher erythrocyte LA levels than control rats. This increase was mainly at the expense of OL and occured in a dose?dependent manner. The feeding of n?6 PUFA rich diets did not modify AA levels to a significant extent. The feeding of the n?3 PUFA rich diets (flaxseed oil & SLO) increased n?3 fatty acids and decreased n?6 fatty acids in erythrocyte membranes. These alterations were more pronounced in rats fed SLO than flaxseed oil diets. The osmotic fragility of rat erythrocytes following incubation in NaCl solutions (increasing in concentration from 0% to 0.85%) were less resistant to hemolysis than those of control rats for all dietary oils except the OO diet. These changes were significant with the feeding of EPO5, FO5, F10 and SLO10. The data from this study suggest that lower resistance to hemolysis in the rat erythrocyte is related to alterations in the fatty acids of erythrocyte membrane lipids and that highly unsaturated dietary fatty acids can impair resistance to hemolysis.
