ESSENTIAL FATTY-ACIDS AND THE MAJOR URINARY METABOLITES OF THE E-PROSTAGLANDINS IN THRIVING NEONATES AND IN INFANTS RECEIVING PARENTERAL FAT EMULSIONS

The administration of parenteral fat emulsion—Intralipid, a preparation rich in the essential fatty acid (EFA), linoleic acid, is widely used as an integral part of therapy for sick infants along with total parenteral nutrition (TPN). EFAs serve as precursors for prostaglandin (PGs). VVe measured tissue lipid composition and the excretion of the major urinary metabolite of prostaglandins E1 and E2, 7a-hydroxy-5, 11 diketotetranor-prostane-1,16 dioic acid (PGE-M) in three infants who received TPN with Intralipid for prolonged periods and compared these values with control infants. Linolcic acid is incorporated into the major lipid classes of the plasma, RBC, and tissues in the infants receiving Intralipid. Concomitantly with the increase in the relative concentration of linoleate, a decrease in the higher polyunsaturated fatty acid homologue, arachidonate is apparent. However, the sum of the two EFAs, linoleate and arachidonate, is similar in red blood cells (RBC) and tissue phospholipids of control infants and in infants who received Intralipid. A significant difference between the PGE- M excretion in the group of infants before and after the administration of Intralipid also is apparent (P < 0.05). Differences in the urinary excretion of PGE-M are seen between the control group and the infants receiving Intralipid (P < 0.05). PGE-M excretion after the administration of Intralipid is similar to that obtained from infants with EFA-deficiency. © 1979 International Pediatric Research Foundation, Inc.