Ethanolamine phosphoglyceride

The nomenclature rules just cited for phosphatidylcholine and its analogs also hold for ethanolamine phosphoglycerides. Mixtures of the diacyl, alkenyl acyl, and alkyl ether forms are found, for example, in macrophages and neutrophils but in much different ratios than observed for the choline-containing types (Figure 1-11). Again, only the (diacyl) phosphatidylethanol-amine is found in liver cells. These structures will be discussed in more detail in Chapter 5. 

Phospholipase D Behavior. While this enzyme shows no stereospecificity in its attack on the ethanolamine phosphoglycerides, its action in releasing free ethanolamine and a phosphatidic acid provides very clear evidence that the ethanolamine was attached to the parent molecule via a phosphate ester bond. Again, the same protocols and enzyme sources illustrated in Chapter 4 for phosphatidylcholine can be applied very easily to the ethanolamine phosphoglycerides. 

Cholesterol and phospholipids. Most lipids found in myelin are common to other cellular membranes. Cholesterol content is high and cholesterol esters are not present in normal myelin. Phospholipids are also common to other cellular membranes, except for the great quantity of ethanolamine phosphoglycerides in the plasmalogen form. The synthesis of plasmalogens is modified in Zellweger syndrome which is a peroxisomal syndrome that also increases VLCFA. This syndrome and other peroxisomal diseases may cause demyelination (Powers, 2005). 

T able 3 Dietary-Induced Changes in the Major Molecular Species of Diacyl Ethanolamine Phosphoglyceride of Monkey Brain (mol%) ... 

Results are expressed as the percentage of total fatty acids in the fraction analyzed. PL, phospholipids TG, triglycerides CM, gray matter PE, ethanolamine phosphoglycerides TL, total lipids. Diet rich in ALA. 

In a study on 45 different species we found substantial variation in the acyl groups of the phosphoglycerides in the liver. The wide range of polyenoic fatty acid composition in the liver ethanolamine phosphoglyceride (EPG) is shown in Fig. 1, For example, the linoleate was 47% of the total fatty acids in the liver EPG from wild zebra, but less than 1% in marine fish. By contrast, there was a remarkable constancy of the fatty acids of the brain grey matter EPG (Fig. 2)(Crawford, Casperd Sinclair, 1976). 

Polar phospholipid of plasma is mainly choline phosphoglyceride, hence we used red blood cells (R.B.C.s) for ethanolamine phosphoglyceride analysis. Fetal material was obtained at second trimester. 

METABOLIC STUDIES ON ETHANOLAMINE PHOSPHOGLYCERIDES IN NEURONAL AND GLIAL CELLS... 

Abbreviations used DG, diacylglycerols TG, triacylglycerols TPL, total phospholipids PA, phosphatidic acid IPG, CPG and EPG, inositol-choline-, and ethanolamine- phosphoglycerides TLC, thin layer chromatography. 

Values are the average S.E. of determinations carried out on 4 samples. EPG = ethanolamine phosphoglyceride CPG = choline phosphoglyceride SPG = serine phosphoglyceride IPG = inositol phosphoglyceride. ... 

In these experiments rat brain slices were incubated with some phospholipid precursors (choline, arachidonic acid, etc,), and the effect of prostaglandins upon their incorporation and renewal in phospholipids was investigated. When tritiated ethanolamine was used, as the lipid precursor, radioactivity was found not only into ethanolamine phosphoglycerides (EPG) but also in smaller amounts... 

In contrast, results with the ethanolamine phosphoglycerides have... 

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