Characterization of Triglycerides and Lipogenesis of Serum Lipids from Dietary or Hepatic Origin: a LC-MS/MS and GC/MS Stable-Isotope Tracer Approach

摘要

Two MS techniques, LC-ESI-MS/MS and GC-MS, were utilized for TG profiling and MIDA. They confirmed the higher quality purification of each lipoprotein fraction (VLDL and chylomicron) derived from the immunoaffinity separation versus the ultracentrifugation one. In each fraction (VLDL and chylomicron), five major palmitatecontaining TG subfamilies were identified by means of LC-ESI-MS/MS. The contributions of TG species were quantitatively different when comparing the subfamilies of each lipoprotein fraction. The estimation of DNL in the TG subfamilies of the respective fractions differed as well. Importantly, de novo lipogenesis was detected in the chylomicron fraction suggesting the occurrence of intestinal DNL. The application of this methodology will facilitate mechanistic studies of the role of postprandial lipids originating in the liver and the intestine and their respective contributions to dyslipidemia.