Étude comparative de la biosynthèse des phosphatidylcholines dans les neurones et les cellules gliales du cerveau de poulet

Freysz, L.; Mandel, P.

doi:10.1016/0014-5793(74)80905-1

Cited by 18 publications

(4 citation statements)

References 19 publications

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“…Thirdly, the differentiation of new cell types, including astrocytes and oligodendrocytes, may be related to the synthesis of new isoenzymes with different affinities. This hypothesis is consistent with the finding that the K, values for alkylacylglycerolphosphocholine, diacylglycerolphosphoethanolamine, and alkylacylglycerolphosphoethanolamine transferases for their respective CDP-bases increase during the period of glial cell differentiation, and with reports of different apparent K , values in neuronal and glial cells for phosphocholine and phosphoethanolamine transferases (Freysz and Mandel, 1974;Roberti et al, 1975). The fact that the affinity of microsomal diacylglycerolphosphocholine transferase changes very little during brain development may indicate that the affinities of the different isoenzyrnes for CDPcholine are very similar.…”

Section: Freysz Et a Lsupporting

confidence: 91%

“…This pronounced increase in the specific activities of both enzymes occurs a few days after the beginning of the differentiation of glial cells, during the period which corresponds to the most active deposition of myelin and the greatest deposition of ethanolamine and choline glycerophospholipids (Freysz et al, 1971;Shaikh and Palmer, 1976). During this same period, the relative yield of microsomes also increased markedly.…”

Section: Discussionmentioning

confidence: 89%

“…Several hypotheses can be put forward to explain the changes in the affinity of phosphocholine and phosphoethanolamine transferases. Firstly, the increase of the apparent K , values may be due to the synthesis of competitive inhibitors, like cytidine nucleotides (Freysz and Mandel, 1974;. This hypothesis seems rather unlikely since during the period of glial cell differentiation there is a dramatic decrease of cytidine nucleotides (Wegelin and Manzoli, 1967;Manzoli and Wegelin, 1969).…”

Section: Freysz Et a Lmentioning

confidence: 99%

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Activites of Enzymes Synthesizing Diacyl, Alkylacyl, and Alkenylacyl Glycerophosphoethanolamine and Glycerophosphocholine During Development of Chicken Brain

Freysz¹,

Horrocks

Mandel³

1980

Journal of Neurochemistry

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Ethanolamine and choline glycerophospholipids are the major phospholipids of brain membranes. During brain development, the accumulation of these phospholipids is most intense when myelination occurs. In order to gain knowledge about the regulatory mechanisms for synthesis of these lipids in relation to membrane synthesis, we investigated the activities of the 1,2‐diradyl‐sn‐gIycerol: CDPethanolamine phosphoethanolarnine transferase and 1,2‐diradyl‐sri‐glycerol:CDPcholine phosphocholine transferase during chicken brain development. Diacyl, alkenylacyl, and alkylacylglycerols are substrates for both enzymes. The specific activities of microsomal phospho‐ethanolamine and phosphocholine transferases are constant between the 8th and 18th day of embryonic life. The specific activities of both enzymes double around hatching, which is the period of intense myelination and marked ac‐cumulation of ethanolamine and choline glycerophospholipids in brain. At the same time, the amount of microsomes increases by 50%; thus the total activities increase threefold. Four days after hatching the specific activities of both enzymes are at adult values. Similar results were obtained in the presence of exogenous diacyl or alkylacylglycerols. During brain development the apparent Km, value of rnicrosomal phosphoethanolamine transferase for CDP ethanolamine increases when assayed with diaclyglycerols or alkylacyl‐glycerols a s lipid substrates. The apparent Km, value of phosphocholine trans‐ferase for CDP choline does not change during brain development in the presence of exogenous diacylglycerols, but increases in the presence of exogenous alkylacylglycerols. These changes in Km, values may be due to the appearance of glial isoenzyme at the beginning of myelination. The apparent Km, values of diacylglycerol phosphocholine, alklyacylglycerol phosphocholine, and diacyl‐glycerol phosphoethanolamine transferases for their CDP bases are similar in adult brain microsomes and are threefold higher than the apparent Km, value of alkylacylglycerolphosphoethanolamine transferase. The high affinity of alkylacylglycerolphosphoethanolamine transferase for CDPethanolamine may be responsible for the preferential synthesis of ethanolamine plasmalogens in brain.

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Section: Freysz Et a Lsupporting

confidence: 91%

Section: Discussionmentioning

confidence: 89%

Section: Freysz Et a Lmentioning

confidence: 99%

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Activites of Enzymes Synthesizing Diacyl, Alkylacyl, and Alkenylacyl Glycerophosphoethanolamine and Glycerophosphocholine During Development of Chicken Brain

Freysz¹,

Horrocks

Mandel³

1980

Journal of Neurochemistry

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“…On the other hand, if the alkylacyl-GPE synthesizing activity is referred to deoxyribonucleic acid (DNA) content (and presumably to number of cells) rather than to protein, then a higher activity in glia is obtainable as compared to neurons, since the protein/DNA ratio in glial cells is ca. three times that in neurons (25). This consideration might indicate that glial ceils are endowed/unit cell of a higher potentiality for alkylacyl-GPE synthesis than neurons, and, presumably, this could be reflected in a higher rate of synthesis of ethanolamine plasmalogens in glia as compared to neuronal cells through the successive step catalyzed by the desaturase activity, a problem which is currently under investigation in our laboratory.…”

Section: Discussionmentioning

confidence: 90%

Enzymic synthesis of 1‐alkyl‐2‐acyl‐sn‐glycero‐3‐phosphorylethanolamine through ethanolaminephosphotransferase activity in the neuronal and glial cells of rabbit in vitro

Roberti

Binaglia

Francescangeli

et al. 1975

Lipids

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The transfer of radioactivity from cytidine-5'-diphosphate ethanolamine into 1-alkyl-2-acyl-sn-glycerophosphorylethanolamine of neuronal and glial cells from adult rabbit brain cortex has been investigated in vitro. The synthesis of 1-alkyl-2-acyl-sn-glycerophosphorylethanolamine in both cell populations was stimulated 23-25-fold by the addition of 6 mM alkylacylglycerol. The neuronal cell-enriched fraction was found to possess/unit protein a 1.7-1.8-fold ethanolaminephosphotransferase activity (EC 2.7.8.1), as compared to the glial fraction, when saturating concentrations (6 mM) of alkylacylglycerols were added in the incubation system. The neuronal/glial ratio was 2.6-2.8 in the absence of lipid acceptor or with low concentrations of alkylacylglycerol. Under most favorable conditions, 6.4 and 3.3 nmoles 1-alkyl-2-acyl-sn-glycerophosphorylethanolamine/mg protein/30 min was obtained for neurons and glia, respectively. Various kinetic properties of the 1-alkyl-2-acyl-sn-glycerophosphorylethanolamine synthesizing phosphotransferase activity were found to be similar both in neurons and glia.

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Studies on choline and ethanolamine phosphoglyceride biosynthesis in developing rabbit brain

Fimbres

Saenz

Smith

et al. 1980

J of Neuroscience Research

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Activities of cholinephosphotransferase (EC 2.7.8.2) and ethanolaminephosphotransferase (EC 2.7.8.1) were evaluated in microsomal preparations derived from rabbit cerebrum. Animals ranged in age from nineteen days' gestation through two months of postnatal development. Under optimal conditions the properties of these transferases in rabbit brain were remarkably similar relative to pH, divalent cation requirements, and apparent-Km values for the CDP-intermediates and the lipid acceptor, respectively. Cholinephosphotransferase-specific activity exhibited a dramatic rise during the last 15%-20% of fetal life and a second rise to a maximum near the 15th postnatal day. Ethanolaminephosphotransferase-specific activity exhibited a similar, but less striking age-related increase during the same period. Growth of rabbit cerebrum as determined by weight, increased 30-fold during this same period (24 days gestation to the 19th postnatal day). Specific activities of these transferase were similar in brain preparations from mid-fetal and early adult rabbits. The maximum specific activity of cholinephosphotransferase exceeded that of ethanolaminephosphotransferase by 3-4-fold. Age-related changes in the specific activities of these transferases appear to correlate with the developmental pattern of morphological and compositional events occurring in rabbit cerebrum during the last third of gestation and the first three weeks of postnatal life.

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Étude comparative de la biosynthèse des phosphatidylcholines dans les neurones et les cellules gliales du cerveau de poulet

Cited by 18 publications

References 19 publications

Activites of Enzymes Synthesizing Diacyl, Alkylacyl, and Alkenylacyl Glycerophosphoethanolamine and Glycerophosphocholine During Development of Chicken Brain

Activites of Enzymes Synthesizing Diacyl, Alkylacyl, and Alkenylacyl Glycerophosphoethanolamine and Glycerophosphocholine During Development of Chicken Brain

Enzymic synthesis of 1‐alkyl‐2‐acyl‐sn‐glycero‐3‐phosphorylethanolamine through ethanolaminephosphotransferase activity in the neuronal and glial cells of rabbit in vitro

Studies on choline and ethanolamine phosphoglyceride biosynthesis in developing rabbit brain

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