Pattern of Incorporation of 32P into the Phospholipids of the Rat Tapeworm Hymenolepis diminuta

1971 ◽  
Vol 49 (11) ◽  
pp. 1209-1212 ◽  
Author(s):  
R. A. Webb ◽  
D. F. Mettrick
Keyword(s):  
Fatty Acid ◽  
Phosphatidic Acid ◽  
De Novo ◽  
Hymenolepis Diminuta ◽  
De Novo Synthesis ◽  
Major Pathway ◽  
Acid Incorporation ◽  
Fatty Acid Incorporation

The incorporation of 32P-orthophosphate into the phospholipids of H. diminuta was followed for up to 4 h in vitro. The rates and patterns of incorporation of 32P into phosphatidc acid, phosphoinositide, phosphatidylserine, lecithin, lysolecithin, and phosphatidylethanolamine plus cardiolipin indicated that H. diminuta possesses mechanisms for the de novo synthesis of these phospholipids. The major pathway utilized by H. diminuta in fatty acid incorporation was via phosphatidic acid.

A comparison of the rates of incorporation of fatty acids during the rapid synthesis in vitro of endogenous triacylglycerols by neuronal nuclei

1983 ◽  
Vol 61 (12) ◽  
pp. 1265-1271 ◽  
Author(s):  
R. Roy Baker ◽  
Huu-yi Chang
Keyword(s):  
Fatty Acids ◽  
Fatty Acid ◽  
Acyl Transferase ◽  
Rapid Synthesis ◽  
Neuronal Nuclei ◽  
Triacylglycerol Synthesis ◽  
Acid Incorporation ◽  
Fatty Acid Incorporation ◽  
Specific Activities

The incorporation of radioactive palmitate, oleate, linoleate, and arachidonate into endogenous triacylglycerols was followed in vitro using neuronal nuclei (N1) isolated from cerebral cortices of 15-day-old rabbits. Specific rates of incorporation of fatty acids into N1 triacylglycerols were 33–42 times and more than 100 times the corresponding values for cerebral cortex homogenates and microsomal fractions (P3), respectively. Acyl-CoA synthetase specific activities in N1 were 2.2 to 3.2 times the specific rates for fatty acid incorporation into N1 triacylglycerols. Using single fatty acids, N1 acyl-CoA synthetase showed a preference for linoleate which was more highly marked in linoleate–palmitate and linoleate–arachidonate competitions. In fatty acid incorporation into N1 triacylglycerols a preference for linoleate in competition with palmitate was noted; however, there was also a relatively higher utilization of arachidonate shown competitively than was noted in acyl-CoA synthesis. The data suggested that N1 diacylglycerol acyl transferase shows a selectivity for arachidonoyl-CoA in comparison with CoA esters of palmitate or oleate. Molecular class analyses of radioactive triacylglycerol products indicated that native endogenous N1 diacylglycerols bearing arachidonate or fatty acids of equal or higher unsaturation were used preferentially in N1 triacylglycerol synthesis. This preference was significantly decreased when higher levels of endogenous diacylglycerols were produced in N1 following a phospholipase C preincubation.

Evidence that hepatic triglycerides provide acylglycerides for synthesis of bile phosphatidylcholines

1994 ◽  
Vol 267 (6) ◽  
pp. G1028-G1034
Author(s):  
G. M. Patton ◽  
J. M. Fasulo ◽  
S. J. Robins
Keyword(s):  
Fatty Acid ◽  
Phosphatidic Acid ◽  
Rat Liver ◽  
De Novo ◽  
Specific Activity ◽  
De Novo Synthesis ◽  
Chase Period ◽  
Phosphatidic Acids

To determine the biochemical origin of bile phosphatidylcholines (PCs), rat liver perfusions with 16:1 fatty acid (FA) and [3H]glycerol were performed to generate novel radiolabeled bile and liver PCs and their hepatic glyceride precursors. Results showed total equilibration of bile and liver 16:1-16:1 PC when the specific activity of precursor glycerol-3-phosphate was kept constant. However, when the specific activity of glycerol-3-phosphate decreased during the labeling period and during a prolonged chase period with 17:1 FA and nonradiolabeled glycerol, the specific activity of bile 16:1-16:1 PC was appreciably higher than this same PC in the liver and during the chase period was even higher than its hepatic 16:1-16:1 acylglycerol precursors, phosphatidic acid and diglyceride. During the chase period with 17:1 FA, new radiolabeled 16:1-17:1 PC was formed, and again the specific activity of this PC in bile was greater than this PC and 16:1-17:1 phosphatidic acid and diglyceride in the liver. Only the specific activity of liver 16:1-16:1-(FA) triglyceride equaled or was high enough to support the formation of new bile 16:1-16:1 PC. These studies indicate that bile PCs do not directly derive from preexisting hepatic PCs or by de novo synthesis through phosphatidic acids and diglycerides, but likely originate by remodeling from a pool of hepatic triglycerides.

Impairment of Lipid Metabolism Due to Deficiency of Pyridoxal-5-phosphate and/or Activated Immune system: its Interpretation

Pteridines ◽  
2000 ◽  
Vol 11 (4) ◽  
pp. 107-120 ◽  
Author(s):  
Vera Rudzite ◽  
Edite Jurika ◽  
Matthias Jäger ◽  
Dietmar Fuchs
Keyword(s):  
Cell Cycle ◽  
Fatty Acid ◽  
Immune System ◽  
Membrane Fluidity ◽  
Incubation Medium ◽  
Phospholipid Biosynthesis ◽  
P Deficiency ◽  
Acid Incorporation ◽  
Fatty Acid Incorporation

Abstract Impairment of lipid metabolism due to excess metabolite accumulation induced by pyridoxal-5-phosphate (P-5-P)-deficiency and/or stimulated immune system has been studied and interpreted. Decreased amounts of phospholipids as well as deviations in phospholipid classes and fatty acid composition of phospholipids have been demonstrated due to kynurenine accumulation in the blood of P-5-P-deficient cardiovascular patients and white rats as well as in cardiovascular patients with activated immune system identified by an increased neopterin concentration in the blood (dilated cardiomyopathy). The addition of P-5-P to the incubation medium for phospholipid biosynthesis in vitro did not change fatty acid incorporation into phospholipids, whereas it normalised fatty acid incorporation into phospholipids in liver homogenates received from P-5-P-deficient rats: The addition of kynurenine, neopterin and noradrenalin (accumulated m isolated heart tissue after addition of kynurenine and neopterin to incubation medium for isolated heart) to incubation medium for phospholipid biosynthesis in vitro induced an increase of saturated and a decrease of polyunsaturated fatty acid incorporation into phospholipids. These changes in fatty acid incorporation into phospholipids were followed by increased cholesterol concentrations in samples and an increased cholesterol/phospholipid ratio. Our results suggest that these changes in lipids are characteristic for decreased membrane fluidity, depressed cell cycle and lowered possibility of phospholipids to keep cholesterol in solution. P-5-P-deficiency is also accompanied with excess accumulation of homocysteine in the blood. The addition of L-homocysteine to the incubation medium for phospholipid biosynthesis in vitro was followed by inverse changes in fatty acid incorporation into phospholipids when compared with kynurenine, neopterin and noradrenalin. L-homocysteine induced a decrease of saturated and an increase of polyunsaturated fatty acid incorporation into phospholipids. The cholesterol concentration decreased in samples and the cholesterol/ phospholipid ratio decreased, too . These findings suggest that changes in lipids induced by L-homocysteine are characteristic for increased membrane fluidity and stimulated cell cycle. In this study, we have observed a similar effect to L-homocysteine effect when L-homocysteine, L-tryptophan and 5,6,7,8-tetrahydrobiopterin were added to the incubation medium for phospholipid biosynthesis in vitro. The comparison of our results with data from the literature allows to suggest that excess metabolite accumulation due to activated formation and inactivated catabolism of it plays a significant role in quantitative and qualitative changes of lipids, especially phospholipids, and therefore participates in the regulation of membrane fluidity, cell cycle of normal and malignant cells as well as in keeping cholesterol in the state of solution.

A micromass culture method for rat embryonic neural cells

1983 ◽  
Vol 61 (1) ◽  
pp. 247-262
Author(s):  
O.P. Flint
Keyword(s):  
De Novo ◽  
Culture Method ◽  
Neural Cells ◽  
Gamma Amino Butyric Acid ◽  
De Novo Synthesis ◽  
Rat Embryo ◽  
Amino Butyric Acid ◽  
Acid Incorporation

A method of culturing early (13-day) rat embryo neural cells is described. Undifferentiated neural epithelium is disaggregated and cultured in small discrete islands. Cells that destined to differentiate as neurons actively segregate from the other cells in the island and aggregate together into small clumps. Other cells flatten and attach to the substrate and resemble typical fibroblasts throughout the culture period. The clumps of preneuron cells spread out forming large irregular foci. Spreading is mediated by active cell movements. Cells in the foci differentiate as a pure population of neurons identifiable by specific inhibition of 3H-labelled gamma-amino butyric acid incorporation or by labelling with a monoclonal antibody to GQ-ganglioside. The ganglioside is not found on the cell surface at the start of culture after trypsinization, but emerges during the 5 days of culture. The antigen is similarly not present in the embryonic mesencephalon in vivo at 13 days post coitum, only emerging later in the differentiated midbrain. There is thus an apparent de novo synthesis, which is paralleled in vivo and in vitro.

In vivo study of the biosynthesis of long-chain fatty acids using deuterated water

1995 ◽  
Vol 269 (2) ◽  
pp. E247-E252 ◽  
Author(s):  
H. O. Ajie ◽  
M. J. Connor ◽  
W. N. Lee ◽  
S. Bassilian ◽  
E. A. Bergner ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Fatty Acid ◽  
De Novo ◽  
Chain Elongation ◽  
Deuterated Water ◽  
De Novo Synthesis ◽  
Isotopomer Distribution ◽  
Long Chain ◽  
Mass Isotopomer

To determine the contributions of preexisting fatty acid, de novo synthesis, and chain elongation in long-chain fatty acid (LCFA) synthesis, the synthesis of LCFAs, palmitate (16:0), stearate (18:0), arachidate (20:0), behenate (22:0), and lignocerate (24:0), in the epidermis, liver, and spinal cord was determined using deuterated water and mass isotopomer distribution analysis in hairless mice and Sprague-Dawley rats. Animals were given 4% deuterated water for 5 days or 8 wk in their drinking water. Blood was withdrawn at the end of these times for the determination of deuterium enrichment, and the animals were killed to isolate the various tissues for lipid extraction for the determination of the mass isotopomer distributions. The mass isotopomer distributions in LCFA were incompatible with synthesis from a single pool of primer. The synthesis of palmitate, stearate, arachidate, behenate, and lignocerate followed the expected biochemical pathways for the synthesis of LCFAs. On average, three deuterium atoms were incorporated for every addition of an acetyl unit. The isotopomer distribution resulting from chain elongation and de novo synthesis can be described by the linear combination of two binomial distributions. The proportions of preexisting, chain elongation, and de novo-synthesized fatty acids as a percentage of the total fatty acids were determined using multiple linear regression analysis. Fractional synthesis was found to vary, depending on the tissue type and the fatty acid, from 47 to 87%. A substantial fraction (24-40%) of the newly synthesized molecules was derived from chain elongation of unlabeled (recycled) palmitate.

The composition and metabolism of fatty acids in Ips paraconfusus Lanier (Coleoptera: Scolytidae)

1972 ◽  
Vol 50 (10) ◽  
pp. 1263-1267 ◽  
Author(s):  
K. R. Penner ◽  
J. S. Barlow
Keyword(s):  
Fatty Acids ◽  
Fatty Acid Composition ◽  
Fatty Acid ◽  
Sexual Dimorphism ◽  
Acid Composition ◽  
De Novo ◽  
Monounsaturated Fatty Acids ◽  
Ips Paraconfusus ◽  
Chain Elongation ◽  
De Novo Synthesis

The fatty acid composition of newly emerged Ips paraconfusus Lanier shows no sexual dimorphism and is approximately as follows: C14:0, 0.5%; C16:0, 23.0%; C16:1, 6%; C18:0, 3%; C18:1, 55%; C18:2, 9%; C18:3, 2%. Both sexes, but particularly the female, use up fatty acids, particularly the monounsaturated acids, during reproduction. Isotope from 1-14C-acetate injected into newly emerged females appeared in all saturated and monounsaturated fatty acids within 30 min. There was evidence of de novo synthesis of C14:0 and C16:0, chain elongation of C16:0 to C18:0, and desaturation of C16:0 and C18:0 to yield C16:1 and C18:1 respectively.

Effects of chronic beta-amyloid treatment on fatty acid incorporation into rat brain

1996 ◽  
Vol 17 (2) ◽  
pp. 301-309 ◽  
Author(s):  
Sheryl K. Brining ◽  
Collins R. Jones ◽  
Michael C.J. Chang
Keyword(s):  
Fatty Acid ◽  
Rat Brain ◽  
Beta Amyloid ◽  
Acid Incorporation ◽  
Fatty Acid Incorporation
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