George M. Patton

Extraction of phospholipids and analysis of phospholipid molecular species.

Publisher Summary The chapter presents a discussion on extraction of phospholipids and analysis of phospholipid molecular species. The phospholipids (PLs) are a family of molecules that, with the exception of sphingomyelin (SM), are characterized by the presence of a phosphate group esterified to the sn -3 position of glycerol and 1 (lyso-PLs) to 4 (cardiolipin) acyl residues attached through an ester bond at the sn -2 position of glycerol and either an ester (acyl), ether (alkyl), or vinyl ether (alkenyl) bond at the sn -1 position of glycerol. The separation of a particular PL class into its various molecular species can be readily accomplished by reversed-phase chromatography of either the intact PL or after the PL has been converted to an appropriate derivative. There are advantages and disadvantages to both procedures. The first step in the fractionation of PLs is to extract the lipids from the tissue. This is accomplished by extracting the tissue with a combination of organic solvents: (1) the lipids are chemically stable, (2) any enzymes that might metabolize the lipids are denatured, and (3) where miscibility with water is sufficient so that a single phase is formed (to ensure an efficient extraction).

Gender differences in the development of hyperlipemia and atherosclerosis in hybrid hamsters

In response to a diet enriched in saturated fat and cholesterol (CH), male Syrian hamsters develop hyperlipemia and changes of early atherosclerosis. However, it has not been determined if female hamsters are equally susceptible to an atherogenic diet. Male and female hamsters of the F1B hybrid strain (Bio Breeders, Fitchburg, MA) were fed either a chow diet or this diet (HiFat) with added saturated fat (10% coconut oil) and CH (0.05%) for up to 12 weeks. Female hamsters ate significantly more than males, and with the HiFat diet gained threefold more weight than males. However, with the HiFat diet, serum triglycerides (TGs) and CH were markedly increased only in male hamsters. Furthermore, only in males was there a significant increase in stainable fat in the aorta that corresponded to an increase in subintimal foam cells. In freely feeding males, the largest percentage increase in serum CH was in the TG-rich fraction of lipoproteins. After females were castrated, serum TG and CH levels increased to the same extent as in males. These studies demonstrate a profound gender difference in response to an atherogenic diet in these hamsters that has parallels to the lipid patterns of humans and their susceptibility to atherosclerosis.

Analysis of lipids by high performance liquid chromatography. Part II: Phospholipids

Analyse des lipides par H.P.L.C. Hydrolyse enzymatique des phospholipides par des lipases purs purification des diglycerides. Benzoylation des diglycerides et des ceramides separation des alkenylacyl, des alkylacyl et des diacylbenzoyl glycerides

Chapter 10 HPLC of Molecular Species of Glycerophospholipids in Studies of Lipoproteins and Lipid Transport

Publisher Summary This chapter discusses the high pressure liquid chromatography (HPLC) analysis of the major diacylphospholipids with the premise that (1) the biologic behavior of these phospholipids are a direct consequence of the specific acyl group composition of individual molecules, and (2) the specific molecular species composition of phospholipids that participate in biologic reactions can best be determined by HPLC. The chapter presents a working method of molecular species analysis using HPLC, illustrates the extent to which specific molecular species of phosphatidylcholine can participate in selected aspects of lipid transport, and suggests key points in the overall scheme of lipid transport where the selective participation of specific molecular species of phosphatidylcholine could have a major regulatory influence. The biologic behavior of any single phospholipid molecule may be a function of the particular acyl groups that comprise that molecule.. Although HPLC has a number of technical features to generally recommend its use in biologic studies, the major advantage of HPLC in studies of phospholipids such as phosphatidylcholines would be its potential for tracing the transport and metabolism of single, whole molecules.