Effect of diet on the fatty acid and molecular species composition of dog retina phospholipids

Dogs were born to mothers fed commercial diets low or enriched in n-3 fatty acids and raised on those diets until they were about 50 d old. Retinas we re removed, lipids were extracted, and total phospholipids were analyzed fo r fatty acid and molecular species composition. Animals from the low n-3 gr oup had significantly lower retinal levels of 22:6n-3 and higher levels of n-6 fatty acids, especially 20:4n-6 and 22:5n-6. There was no difference in the retinal levels of 18:2n-6, and only small differences were found in sa turated and monounsaturated fatty acids. The most dramatic differences in m olecular species occurred in 22:6n-3-22:6n-3 (4.7 vs. 0.8%) and 18:0-22:6n- 3 (27.6 vs. 14.4%); total molecular species containing 22:6n-3 were signifi cantly lower in the low n-3 group (45.5 vs. 24.0%). Molecular species conta ining 20:4n-6 and 22:5n-6 were greater in the low n-3 animals (13.0 vs. 25. 7%), as were molecular species containing only saturated and monounsaturate d fatty acids (40.8 vs. 35.4%). These results show that modest differences in the amount of n-3 fatty acids in the diets of dogs can have profound eff ects on the fatty acid and molecular species composition of their retinas.