Effects of Maternal Dietary n-3 and n-6 Fatty Acids (Pre- and Post-Δ6 Desaturation) on Tissue Glycerophospholipid Fatty Acid Compositions in Dams and Suckling Mice

Abstract

The present study examined the effects of supplementation of either 18:3n-3 or a mixture of its post-Δ6-desaturation metabolites, 20:5n-3/22:6n-3, in combination with either 18:2n-6 or its immediate Δ6-desaturation product, 18:3n-6, in the maternal diet (n-3 to n-6 ratio at 0.25) on brain, liver, heart, and kidney glycerophospholipid fatty acid composition in dams (B6D2F₁ mice) and their 12-day-old suckling pups. As expected, n-3 and n-6 fatty acids competed for incorporation into tissue glycerophospho-lipids in both dams and their suckling pups. Feeding a 20:5n-3/22:6n-3 as compared with an 18:3n-3 rich diet increased the tissue levels of 20:5n-3 and 22:5n-3, whereas it decreased those of 20:3n-6 and 20:4n-6. Replacing 18:2n-6 with 18:3n-6 in the maternal diet increased significantly the levels of 18:3n-6, 20:3n-6, and 20:4n-6, whereas it reduced those of 20:5n-3. However, the effects of maternal dietary fats on tissue fatty acid compositions in pups were qualitatively similar to but quantitatively smaller than those in dams. The discrepancy might be due to differences in the composition of fatty acids taken up and synthesized by the dams and that transferred to the pups.