Effects of parenteral nutrition with high doses of linoleate on the developing human liver and brain

Abstract
The developmental changes in the fatty acid composition of ethanolamine phosphoglycerides (EPG) and choline phosphoglycerides (CPG) were studied in the liver and brain of 18 newborn infants with gestational ages ranging from 20 to 44 wk. A small group of five newborns receiving total parenteral nutrition (TPN) with high doses of linoleic acid (18∶2ω6) was also studied and compared to controls of the same gestational age to look for effects on the developmental fatty acid patterns of liver and brain EPG and CPG. TPN with Intralipid 20% was given for 4–12 days, the total fat intake being 14.7–90 g (mean ±S.D.=47.1±29.8 g). The main developmental changes in the liver and brain of the control group were an increase in 22∶6ω3 (docosahexaenoic acid) at the end of gestation and a linear decrease in 20∶4ω6 (arachidonic acid) and 18∶1ω9 (oleic acid) in EPG and CPG. A very good correlation in the percent values of these fatty acids in the brain and liver tissues was obtained. Very significant changes in the fatty acid composition of liver EPG and CPG could be found in the infants receiving TPN with Intralipidmainly an increase in 18∶2ω6, a decrease in the linoleate elongation/desaturation to longer members of the series and a decrease in the 22∶6ω3 levels of liver EPG and CPG. In the brain, only an increase in the 18∶2ω6 value of CPG, not accompanied by any increase in the longer ω6 fatty acids, could be detected. Possible adverse effects of high doses of 18∶2ω6 on the tissue levels of long chain polyunsaturated fatty acids (PUFA), especially of 22∶6ω3, are discussed.