title: Early postnatal development in the rat is characterized by accumulation of highly unsaturated triacylglycerols.
abstract: Our objective was to determine the quantitative changes of individual triacylglycerol (TG) species in liver and carcass during early postnatal growth. Pregnant rats were killed at d 21 of pregnancy, and neonatal rats were killed at d 3 or 9 after birth. Quantitative changes in fatty acids and TG species of fetal/neonatal liver and carcass were determined using capillary gas liquid chromatography. At postnatal d 3 or 9 compared with fetal d 21, total carcass TG increased 11- to 12-fold, with nonessential fatty acids increasing 8- to 9-fold, n-6 essential fatty acids (EFA) increasing 34- to 44-fold, and n-3 EFA increasing 19- to 29-fold, respectively. Total neonatal liver TG increased 13-fold from fetal d 21 to postnatal d 3, with a 6-fold increase in non-EFA, a 34-fold increase in total n-6 EFA and a 65-fold increase in total n-3 EFA. At postnatal d 3 compared with fetal d 21, larger molecular weight liver TG classes (C56-C64) increased 68-fold, followed by lower molecular weight TG classes C40-C48 (19-fold) with only a 6-fold increase in C50-C54. In liver, highly unsaturated TG classes (C56-C64) accounted for 49% of total TG at postnatal d 3 and consisted mainly of arachidonic, docosahexaenoic, and linoleic acids accompanied by palmitic and oleic acids. During early postnatal development, TG species containing one, two, or even three 20-22 EFA may be structurally important themselves or serve as direct substrates for synthesis of phospholipids.(ABSTRACT TRUNCATED AT 250 WORDS)
authors.affiliation: Department of Nutritional Sciences, Faculty of Medicine, University of Toronto, Ontario, Canada.
authors.forename: Z Y
authors.initials: ZY
authors.lastname: Chen
authors.forename: S C
authors.initials: SC
authors.lastname: Cunnane
mesh_terms: D000818:Animals; D000831:Animals, Newborn / Q000254:growth & development / Q000378:metabolism*; D005231:Fatty Acids, Unsaturated / Q000737:chemistry / Q000378:metabolism; D005260:Female; D005333:Fetus / Q000378:metabolism; D008099:Liver / Q000254:growth & development / Q000378:metabolism; D011247:Pregnancy; D051381:Rats; D011919:Rats, Inbred Strains; D014280:Triglycerides / Q000737:chemistry / Q000378:metabolism*
chemical_list: D005231:Fatty Acids, Unsaturated; D014280:Triglycerides