Postnatal changes in the phospholipid composition of livers from young lambs.

Abstract

AbstractThe total lipids were extracted from the livers of newborn lambs, from the livers of lambs during the first week after birth and from the livers of adult sheep. After separation from the nonphospholipids on columns of silicic acid the phospholipids were analyzed by thin layer chromatography and quantitative gas liquid chromatography. In all samples phosphatidyl choline and phosphatidyl ethanolamine together accounted for about 80% of the total liver phospholipids. The phosphatidyl choline‐phosphatidyl ethanolamine ratio in the livers of the newborn lambs was markedly less than the ratio in the livers of the adult sheep. Moreover there was a pronounced increase in the phosphatidyl cholinephosphatidyl ethanolamine ratio in the livers of the lambs during the first week after birth. In the liver phospholipids of the lambs the concentration of phosphatidyl inositol was lower and the concentrations of phosphatidyl serine and sphingomyelin were greater than the corresponding concentrations in the liver phospholipids of the adult sheep. It is proposed that the change in the phosphatidyl choline‐phosphatidyl ethanolamine ratio in the livers of the lambs during the first week after birth is due, at least in part, to the marked change that occurs in the linoleic acid‐arachidonic acid ratio in the tissues of the lamb during this period.