RETINAL FATTY-ACIDS OF PIGLETS FED DOCOSAHEXAENOIC AND ARACHIDONIC ACIDS FROM MICROBIAL SOURCES

Docosahexaenoic acid (DHA, 22:6n-3) and arachidonic acid (AA, 20:4n-6) serve important roles in perinatal visual and neural development. A n eonatal pig model was used to determine if dietary supplementation wit h DHA and AA at slightly greater concentrations than normally found in human milk would influence fatty acid accretion in retina. One-day-ol d piglets were assigned to one of four diets (n = 5/group): (i) STD, s tandard diet containing fat similar to infant formula; (ii) STD + DHA, 0.7% of fatty acids as DHA; (iii) STD + AA, 0.9% as AA; and (iv) STD + BOTH, 0.8% as DHA plus 1.0% as AA. After 25 d, fatty acids in retina phosphatidylcholine (PC) and phosphatidylethanolamine (PE) were deter mined. Supplementation with DHA resulted in approximately twofold incr eases (P < 0.05) in PC-DHA (4.88% in STD vs. 10.03% in STD + DHA and 9 .47% in STD + BOTH). Similarly, AA supplementation increased PC-AA 1.3 -1.4-fold (4.47% in STD vs. 6.19% in STD + AA and 5.70% in STD + BOTH) . For PE, supplementation with either fatty acid or in combination res ulted in no significant increases, except for a 1.2-fold increase in D HA for STD + BOTH (32.66%) vs. STD (28.38%). Thus, PC responded to die tary supplementation, with addition of DHA, AA, or BOTH, resulting in increases in respective fatty acids; PE was less responsive, with only STD + BOTH resulting in increased DHA. No significant competition bet ween DHA and AA in incorporation into phospholipids was observed. In c onclusion, consumption of a combination of DHA and AA by neonatal pigs supported accretion of DHA in retina phospholipids, while simultaneou sly supplying the AA-necessary for membrane phospholipids and eicosano id biosynthesis.