PHOSPHOLIPIDS OF EHRLICH ASCITES TUMOR

The following phosphatides (in approximate order of concentration) were studied in cells of the Ehrlich ascites carcinoma incubated in a medium containing inorganic P32: lecithin > sphingomyelin > phosphatidyl ethanolamine = phosphatidyl inositol = phosphatidic acid > choline plasmalogen = phosphatidyl serine > ethanolamine plasmalogen. The specific radioactivity of the diacyl-glycerophosphatide fraction exceeded that of both the plasmalogen and the sphingomyelin – glycerol ether phosphatide fraction, the specific radioactivity of the individual phosphatides being as follows: phosphatidic acid > phosphatidyl inositol > ethanolamine plasmalogen > phosphatidyl ethanolamine = choline plasmalogen = lecithin > sphingomyelin. The microsomal fraction contained more phospholipid, followed by the mitochondrial and nuclear fractions, in that order. The specific radioactivities of the phospholipids of the microsomes and nuclei were greater than that of the mitochondria, chiefly because of the high specific radioactivity of the diacylglycerophosphatide fraction. The high specific radioactivity of the diacylglycerophosphatides was largely the result of a very active incorporation of inorganic P32into phosphatidic acid, particularly in the microsomal fraction. The significance of these findings is discussed.

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METABOLISM OF EHRLICH ASCITES TUMOR IN VITRO: SUBCELLULAR DISTRIBUTION OF PHOSPHOLIPIDS NEWLY FORMED FROM14C-LABELED PRECURSORS

Canadian Journal of Biochemistry ◽

10.1139/o66-166 ◽

1966 ◽

Vol 44 (11) ◽

pp. 1461-1468 ◽

Cited By ~ 3

Author(s):

V. Donisch ◽

R. J. Rossiter

Keyword(s):

Microsomal Fraction ◽

Phosphatidyl Ethanolamine ◽

Lipid Fraction ◽

Specific Radioactivity ◽

Phosphatidyl Inositol ◽

Phosphatidyl Serine ◽

Ethanolamine Phosphatidyl ◽

Ehrlich Ascites ◽

Ethanolamine Plasmalogen

When Ehrlich ascites cells were incubated in a suitable medium containing choline-1,2-14C, ethanolamine-1,2-14C, L-serine-14C, or glycerol-1-14C, radioactivity was recovered from the lipid fraction. With choline-1,2-14C, radioactivity was incorporated into the three choline-containing phospholipids, lecithin, choline plasmalogen, and sphingomyelin. Radioactivity from ethanolamine-1,2-14C was incorporated into phosphatidyl ethanolamine, ethanolamine plasmalogen, choline plasmalogen, and lecithin. Radioactivity from L-serine-14C was incorporated into phosphatidyl serine, serine plasmalogen, and phosphatide acid, with lesser amounts into phosphatidyl ethanolamine, lecithin, ethanolamine plasmalogen, choline plasmalogen, and sphingomyelin. Radioactivity from glycerol-1-14C was incorporated into the glycerophosphatides, phosphatidic acid, lecithin, phosphatidyl ethanolamine, phosphatidyl serine, phosphatidyl inositol, and choline plasmalogen. Radioactivity from this precursor was also incorporated into sphingomyelin.In all instances, radioactivity was recovered from the phosphatides in the nuclear, mitochondrial, and microsomal fractions of the tumor. Usually, the specific radioactivity of the phosphatides in the microsomal fraction exceeded that in the other two subcellular fractions.

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FORMATION OF PHOSPHATIDES FROM C14-LABELLED PRECURSORS IN RAT BRAIN SLICES. EFFECT OF CHLORPROMAZINE

Canadian Journal of Biochemistry and Physiology ◽

10.1139/y63-043 ◽

1963 ◽

Vol 41 (1) ◽

pp. 341-345 ◽

Cited By ~ 3

Author(s):

E. T. Pritchard ◽

R. J. Rossiter

Keyword(s):

Guinea Pig ◽

Phosphatidic Acid ◽

Rat Brain ◽

Phosphatidyl Ethanolamine ◽

Brain Slices ◽

Phosphatidyl Inositol ◽

Phosphatidyl Serine ◽

Inorganic P ◽

The Individual ◽

Guinea Pig Brain

The addition of chlorpromazine (0.1 mM) to slices of rat brain respiring in a suitable medium caused an increase in the incorporation of radioactivity from glycerol-1-C14, glycine-2-C14, and serine-3-C14 into the phospholipids of the slices. There was no increase in the incorporation of radioactivity from choline-1,2-C14 or ethanolamine-1,2-C14. Examination of the individual phosphatides showed an increase in the incorporation of radioactivity from glycerol-1-C14 into phosphatidc acid and phosphatidyl serine, with no change for lecithin and phosphatidyl ethanolamine. Higher concentrations of chlorpromazine (1.0 mM) either inhibited (glycerol-1-C14, choline-1,2-C14), did not significantly alter (glycine-2-C14, ethanolamine-1,2-C14), or stimulated (serine-3-C14) the incorporation of radioactivity into phospholipids. These results are discussed in relation to previous experiments, in which it was found that the addition of chlorpromazine (0.1 mM) to slices of guinea pig brain caused an increase in the incorporation of inorganic P32 into phosphatidic acid, phosphatidyl inositol, phosphatidyl serine, but not into lecithin or phosphatidyl ethanolamine.

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FORMATION OF PHOSPHATIDES FROM C14-LABELLED PRECURSORS IN RAT BRAIN SLICES. EFFECT OF CHLORPROMAZINE

Canadian Journal of Biochemistry and Physiology ◽

10.1139/o63-043 ◽

1963 ◽

Vol 41 (2) ◽

pp. 341-345 ◽

Cited By ~ 5

Author(s):

E. T. Pritchard ◽

R. J. Rossiter

Keyword(s):

Guinea Pig ◽

Phosphatidic Acid ◽

Rat Brain ◽

Phosphatidyl Ethanolamine ◽

Brain Slices ◽

Phosphatidyl Inositol ◽

Phosphatidyl Serine ◽

Inorganic P ◽

The Individual ◽

Guinea Pig Brain

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The hydrolysis of monolayers of phosphatidyl-[Me−14C]choline by phospholipase D

Biochemical Journal ◽

10.1042/bj1130697 ◽

1969 ◽

Vol 113 (4) ◽

pp. 697-705 ◽

Cited By ~ 38

Author(s):

R. H. Quarles ◽

R. M. C. Dawson

Keyword(s):

Phosphatidic Acid ◽

Phospholipase D ◽

High Pressures ◽

Specific Radioactivity ◽

Maximal Activity ◽

Enzymic Hydrolysis ◽

Ph Optimum ◽

High Specific Radioactivity ◽

Rapid Hydrolysis ◽

Hydrolysis Of

1. The hydrolysis of monolayers of phosphatidyl[Me−14C]choline at the air/water interface by phospholipase D (phosphatidylcholine phosphatidohydrolase) was investigated by a surface-radioactivity technique by using a flow counter. 2. Phosphatidylcholine of high specific radioactivity was prepared biosynthetically in good yield from [Me−14C]choline by using Saccharomyces cerevisiae. 3. At initial monolayer pressures between 12 and 25 dynes/cm. the hydrolysis occurred in two stages, an initial slow hydrolysis followed by a rapid hydrolysis. Below 3dynes/cm. and above 28dynes/cm. no enzymic hydrolysis of pure phosphatidylcholine monolayers could be detected. 4. The rapid hydrolysis was proportional to the enzyme concentration in the subphase, its pH optimum was 6·6, and 0·2mm-Ca2+ was required for maximal activity. 5. Hydrolysis of the film was accompanied by a pronounced fall in the surface pressure even though the phosphatidic acid formed did not leave the film. When the pressure fell to low values the hydrolysis ceased even if the film was only partially hydrolysed. 6. Above monolayer pressures of 28dynes/cm. enzymic hydrolysis could be initiated by inclusion of phosphatidic acid (and less effectively stearyl hydrogen sulphate) in the film, although the rates were not appreciably higher than those observed at 25dynes/cm. with a pure phosphatidylcholine film. 7. The initiation of the hydrolysis by phosphatidic acid was facilitated by the inclusion of high Ca2+ concentrations and certain carboxylic acid buffer anions in the subphase, although these did not activate by themselves. 8. The initiation of the hydrolysis at high pressures could not be related to any change in the surface potential brought about by the addition of the long-chain anions to the film, nor could it be ascribed to a surface dilution effect. 9. The results are discussed in relation to previous studies on the hydrolysis of phosphatidylcholine particles by the enzyme and also similar investigations on phosphatidylcholine monolayers with other phospholipases.

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Effects of hormones on Na and H2O transport and on phospholipid metabolism in toad bladder

American Journal of Physiology-Legacy Content ◽

10.1152/ajplegacy.1964.206.1.136 ◽

1964 ◽

Vol 206 (1) ◽

pp. 136-142 ◽

Cited By ~ 4

Author(s):

Sarah Hestrin-Lerner ◽

Lowell E. Hokin

Keyword(s):

Phosphatidic Acid ◽

Sodium Transport ◽

Phosphatidyl Choline ◽

Phosphatidyl Ethanolamine ◽

Phosphatidyl Inositol ◽

Phospholipid Metabolism ◽

Significant Inhibition ◽

Toad Bladder ◽

Cholinergic Agents ◽

Stimulation Of

Incubation of tied paired lobes of bladder from Bufo marinus with 0.025–0.25 U/ml of oxytocin led to appreciable stimulations of both sodium transport and of water transport from the mucosal (luminal) to serosal side. Incubation with aldosterone led to a very slight stimulation of sodium transport, which was statistically significant, in one out of three series. P32 from orthophosphate was incorporated into phosphatidic acid, phosphatidyl ethanolamine, phosphatidyl choline, and phosphatidyl inositol. There were no statistically significant stimulations in the incorporation of P32 into phosphatidic acid, phosphatidyl choline, or phosphatidyl inositol at any concentration of oxytocin. However, there was a statistically significant stimulation of P32 incorporation into phosphatidyl ethanolamine with 0.025 U/ml oxytocin. There was a statistically significant inhibition in incorporation in phosphatidyl choline and phosphatidyl inositol with 0.25 U/ml oxytocin. Cholinergic agents did not produce statistically significant stimulations of either water or sodium transport in toad or turtle bladders, but they led to significant stimulations of incorporation of P32 into some of the phosphatides (phosphatidic acid, phosphatidyl choline, and phosphatidyl inositol in the toad bladder, and phosphatidic acid and phosphatidyl inositol in turtle bladder). On the basis of the fine structure of the epithelium of the toad bladder it is suggested that the phospholipid effect in response to cholinergic agents may be related to stimulation of the secretion of an organic material by the epithelial and/or goblet cells.

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Observations on the in vitro Effects of Chylomicra, Low-Density Lipoproteins and Phospholipids on Human Plasma Euglobulin Lysis

Thrombosis and Haemostasis ◽

10.1055/s-0038-1654971 ◽

1963 ◽

Vol 09 (01) ◽

pp. 164-174 ◽

Cited By ~ 2

Author(s):

Albert R Pappenhagen ◽

J. L Koppel ◽

John H Olwin

Keyword(s):

Human Plasma ◽

Phosphatidyl Ethanolamine ◽

Phosphatidyl Inositol ◽

Plasma Lipoproteins ◽

Low Density ◽

Inhibitory Effects ◽

Soybean Phospholipids ◽

In Vitro Effects ◽

Complete Precipitation

SummaryData have been presented on the in vitro effects of human chylomicra, low-density human plasma lipoproteins, and partially purified preparations of various phospholipids on human plasma euglobulin lysis. Euglobulin lysis was found to be accelerated by preparations of mixed soybean phospholipids (aso-lectin), cephalin, phosphatidyl inositol, phophatidyl serine and phosphatidyl ethanolamine. In contrast, it was found to be inhibited by preparations of human chylomicra, low-density human plasma liproproteins and lecithin. Inhibition of euglobulin lysis produced by any of these three agents could be diminished or completely overcome by the simultaneous presence of suitable levels of any one of the accelerating agents. In all cases studied, both inhibitory and accelerating effects were observed to be concentration-dependent. Evidence has been obtained to suggest that in the case of the accelerating agents the observed increased rate of euglobulin lysis is not a direct effect on lysis itself, but rather is due to more complete precipitation of plasminogen in the presence of these substances. On the other hand, it appears that the inhibitory effects observed are not related to the extent of plasminogen precipitation, but are actually true inhibitions of euglobulin lysis. The possible clinical significance of some of these observations has been briefly discussed.

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