Liver phospholipids

Cowlen MS, Hewitt WR, Schroeder F. 1984. 2-Hexanone potentiation of [14C]ehloroform hepatotoxicity Covalent interaction of a reactive intermediate with rat liver phospholipid. Toxieol Appl Pharmacol 73 478-491. 

Artom, C., Comatzer, W.E. Crowder, M. (1949) The aetion of an analogue of ethanolamine (diethanolamine) on the formation of liver phospholipides. J. biol. Chem., 180, 495-503 Artom, C., Lofland, H.B. Oates, J.A., Jr (1958) In vivo ineorporation of diethanolamine into liver lipides. J. biol. Chem., 233, 833-837... 

Ninhydrin to Detect Lipids on TLC Plates Ninhy-drin reacts specifically with primary amines to form a purplish-blue product. A thin-layer chromatogram of rat liver phospholipids is sprayed with ninhydrin, and the color is allowed to develop. Which phospholipids can be detected in this way ... 

Fig. 3 Separation of standard and liver phospholipids by HPLC on a 5-yttm Nucleosil 5 NH2 stationary phase with an isocratic mobile phase consisting of acetonitrile, methanol, water, and methyl phosphonic acid and subsequent UV and fluorescence detection. The second column was cut off from the eluent stream by valve switching after about 30 min. (Reprinted from Ref. 43 with the kind permission of Analytical Biochemistry.)...

Adinehzadeh M, Reo NV. 1998. Effects of peroxisome proliferators on rat liver phospholipids Sphingomyelin degradation may be involved in hepatotoxic mechanism of perfluorodecanoic acid. Chem Res Toxicol 11 428-440. 

Van Golde LMG, Scherphof GL, Van Deenen LLM. Biosynthetic pathways in the formation of individual molecular species of rat liver phospholipids. Biochem Biophys Acta 1969 176 635-637. 

I ( ) reported that the signs of nickel deprivation in chicks included depressed levels of liver phospholipids, oxidative ability of the liver in the presence of a-glycerophosphate, yellow lipochrome pigments in the shank skin, hematocrits and ultrastructural abnormalities in the liver. 

GC separation of all sixteen CFAMs from heated linseed oil can be achieved by using two different columns (Fig. 5.11 Dobson, Christie and Sebedio, 1996c). In a study where only small amounts of material were available, this approach was used to show that in pregnant rats fed a diet containing CFAMs from heated linseed oil, a cyclohexenyl acid with an E double bond at C-8 was preferentially incorporated into the liver phospholipids of the dam and the pups (Sebedio et al, 1996b). 

Yang and co-workers (45) utilized Ag-HPLC to determine the CLA composition of isolated blood and liver samples of suckling rats fed a mixture of CLA isomers for 7 or 14 d. To minimize the intraisomerization among the CLA isomers, the milk and liver lipid fractions were saponified (KOH/ethanol) and the CLA isomer content determined (as FA) by Ag-HPLC (UV detection at 233 nm) according to the method of Cross and co-workers (44). The authors noted that the distribution patterns of the CLA isomers in the liver lipids were different from those in the diet and milk, including the preferential incorporation of the trans/trans CLA isomers into the liver phospholipid (PL) and TAG fractions. 

Not only are 9c, t and 10t,12c-18 2 isomers metabolized differently, but they also have distinct effects on the metabolism of other fatty acids. Although both isomers resulted in a decrease in the level of arachidonic acid in liver phospholipids of rats, only the 10t,12c-18 2 induced an increase in the C22 polyunsaturated fatty acid in the hver hpids (2). Similarly, CLA supplementation (as a mixture or the 10f,12c isomer) decreased the 18 2n-6 content in hver phospholipids of hamsters (6). At the same time, docosahexaenoic acid was also decreased and a similar pattern was observed in low density lipoprotein-triacylglycerols. Feeding a mixture of CLA for 42 d induced an inaease in the long-chain n-3 fatty acids in rat liver, i.e., 22 5 and 22 6 (7). 

Rat plasma and liver phospholipids (also neutral lipids)... 

Another important class of surfactants is the bile salts (that are synthesized in the liver), phospholipids and cholesterol, which are the main constituents of membranes. These naturally occurring surfactants will also be discussed, briefly, in this section. 

The source of fatty hvers due to deficiency of choline in the diet is much less clear. Choline is a constituent of lecithin and as such might be supposed to aid in phospholipid synthesis. It has actually been shown to increase the turnover rate of phospholipids in the liver, but did not cause any net increase in plasma and liver phospholipids. No increased secretion of phospholipids into the blood could be found, following choline administration to deficient rats (Entenman et al. 1946 ZiLVERSMiT and Dilitzio 1958). The relationship between increased synthesis of phospholipids in the liver and the action of choline on the prevention and cure of fatty livers ( lipotropic action ) is not at all clear. 

Most publications on NVG contain incomplete lipid analyses or none. Craig et al. (1959) examined only some fractions of the liver lipids but not the brain. No chemical analyses were performed in the eight cases of Landing et al. (1964). In the case of Norman et al. (1959) with a cherry-red spot in the macula and hepatomegaly the spleen and liver hexosamine content was increased several-fold, while no neuraminic acid was present. Liver phospholipids but not total lipids were increased. 

Figure 2.4. Isocratic elution of rat liver phospholipids from a column of silica gel with hexane-isopropanol-25 mM phosphate buffer-ethanol-acetic acid (367 490 62 100 0.6 by volume) as mobile phase at a flow-rate of 0.5 mL/min for the first 60 minutes then of 1 mL/min, and with spectrophotometric detection at 205 nm [694]. (Reproduced by kind permission of the authors and of the Journal of Lipid Research, and redrawn from the original publication). Abbreviations NL, neutral lipids PE, phosphatidylethanolamine PA, phosphatidic acid PI, phosphatidylinositol PS, phosphatidylserine DPG, diphosphatidylglycerol PC, phosphatidylcholine SPH, sphingomyelin LPC, lyso- phosphatidylcholine XI, X2, X3 and X4, unidentified lipids.

Entenman and Chaikoff (28) could find little difference between the choline contents of alcohol-ether extracts of plasma when choline reineck-ate was precipitated from solutions at pH 7-8 or from strongly acid solutions (29)—indicating the absence of other nitrogenous compounds that form insoluble reineckates. A difference was observed, however, when the choline content of liver phospholipids was analyzed by the two methods. Taurog, Entenman, and Chaikoff (88) also compared the choline phosphorus ratio of human plasma purified by the colloidal-iron procedure of Folch and Van Slyke (33) with the ratio obtained by their direct extraction procedure. The choline rpho horus ratio by direct extraction was 0.98, and when purified with colloidal iron was 0.96. 

Horrobin, DF, Huang, YS, Cunnane, SC and Manku, MS (1984) Essential fatty acids in plasma, red blood cells and liver phospholipids in common laboratory animals as compared to humans. Lipids, 19, 806-811. 

It was reported in 1950 that in malnourished children with a relative excess of dietary carbohydrate the liver phospholipids increased as the total liver lipid increased, but when the total lipids exceeded 11% of the wet wei t of die liver the phospholipids became stabilized at 4% of the wet weight (Mene ello et al., 1950). No increase in liver phospholipid was found in malnourished children with fatty livers in South Africa, whereas there was an increase in diose children whose fatty liver was not primarily malnutritional in origin (Macdonald, 1960). 

Table 5.14 Principal polyunsaturated fatty acids of the liver phospholipids of zebra and dolphin...

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