EFFECT OF ERUCIC ACID ON INCORPORATION OF ACETATE-1-C14 INTO CHOLESTEROL AND FATTY ACIDS

1959 ◽  
Vol 37 (1) ◽  
pp. 803-810 ◽  
Author(s):  
K. K. Carroll

Young male rats were fed synthetic diets containing either no fat or various individual fatty acids for 3 to 4 weeks. They were then killed and the incorporation of acetate-1-C14 into cholesterol and fatty acids was measured in liver slices and in scrapings of intestinal mucosa. Acetate incorporation into cholesterol by liver slices was much greater in animals fed erucic acid than in those fed no fat, palmitic, stearic, oleic, or linoleic acids. A marked differential was not observed in fatty acid incorporation but values tended to be higher on the fat-free and erucic acid diets. Erucic acid did not stimulate acetate incorporation into cholesterol by mucosa and in general mucosa seemed to be less sensitive to changes in diet. The results are discussed in relation to previously observed effects of erucic acid on cholesterol metabolism.

1959 ◽  
Vol 37 (7) ◽  
pp. 803-810 ◽  
Author(s):  
K. K. Carroll

Young male rats were fed synthetic diets containing either no fat or various individual fatty acids for 3 to 4 weeks. They were then killed and the incorporation of acetate-1-C14 into cholesterol and fatty acids was measured in liver slices and in scrapings of intestinal mucosa. Acetate incorporation into cholesterol by liver slices was much greater in animals fed erucic acid than in those fed no fat, palmitic, stearic, oleic, or linoleic acids. A marked differential was not observed in fatty acid incorporation but values tended to be higher on the fat-free and erucic acid diets. Erucic acid did not stimulate acetate incorporation into cholesterol by mucosa and in general mucosa seemed to be less sensitive to changes in diet. The results are discussed in relation to previously observed effects of erucic acid on cholesterol metabolism.


Pteridines ◽  
1993 ◽  
Vol 4 (3) ◽  
pp. 126-130 ◽  
Author(s):  
Vera Rudzite ◽  
Edite Jurika ◽  
Gilbert Reibnegger ◽  
Günter Weiss ◽  
Helmut Wachter ◽  
...  

Summary Incorporation of fatty acids into phospholipids has been investigated using samples of rat liver tissue homogenate, Krebs-Ringer-phosphate buffer (pH = 7.4) containing 0.3% albumin, fatty acid mixture and glyceroL The addition of L-kynurenine (4 nmol/g wet weight), D-eryhro-neopterin (5 and 30 pmol/g wet weight) and noradrenaline (4 nmol/g wet weight) to incubation medium induced an increase of saturated (palmitic acid) and decrease of poly-unsaturated (linoleic and arachidonic acid) fatty acids incorporation into phospholipids. The increase of saturated fatty acids incorporation into phospholipids was more pronounced after addition of neopterin and noradrenaline to the incubation medium while the decrease of linoleic and arachidonic acid synthesis was stimulated most with kynurenine. Moreover, kynurenine stimulated whereas neopterin depressed the oleic acid incorporation into phospholipids. These changes of fatty acid incorporation into phospholipids were followed by increase of cholesterol content in samples containing kynurenine, neopterin or noradrenalin. In contrast, phospholipid content decreased in samples containing kynurenine or noradrenalin, hut was not altered by supplementation of neopterin. Since the addition of kynurenine and neopterin to incubation medium for isolated fog heart resulted in an increased noradrenaline and decreased pyridoxal-5-phosphate content in the tissue, we also added pyridoxal-5-phosphate (4 nmol/g wet weight) to incubation medium for phospholipid biosynthesis. No change of the fatty acid incorporation into phospholipids as welI as the content of phospholipids and cholesterol in samples was observed.


1984 ◽  
Vol 39 (6) ◽  
pp. 593-599 ◽  
Author(s):  
Andreas Sauer ◽  
Klaus-Peter Heise

1.In isolated chloroplasts which are provided with essential exogenous substrates for glycerolipid biosynthesis (sn-G3P and UDPgal) the incorporation of fatty acids into lipids shows the same pH dependence as the fatty acid synthesis itself with a stromal pH optimum close to 8.5. 2.Furthermore high rates of glycerolipid biosynthesis appear to be accompanied by a preferred oleate incorporation as compared to palmitate. 3.Reinvestigations of the sn-G3P requirement of plastid lysophosphatidic acid formation with rapidly prepared substrate-free chloroplast extracts under approximately physiological conditions reveal a lower specificity of the primary sn-G3P acylation for oleate, as recently found for the fatty acid transfer from purified acyl-ACP fractions on to sn-G3P, catalyzed by purified acyl transferase 1. 4.A comparison of calculated stromal sn-G3P levels under physiological conditions (0.1- 0.3 mᴍ) with those, required for half saturation of the primary acylation reaction either with oleate (Km(sn-G3P) = 0.3 mᴍ) or palmitate (Km (sn-G3P) = 0.6 mᴍ) in chloroplast extracts suggests, that both fatty acids to be involved in lysophosphatidic acid formation within chloroplasts, although oleate would be preferred. 5.The latter observation facilitates the understanding of a palmitate accumulation in chloroplast lipid fractions, induced by increasing sn-G3P concentrations in chloroplast sus­pensions. 6.Although stimulating fatty acid synthesis from acetate in intact chloroplasts, acyl-CoA- synthesizing-conditions (presence of CoA and ATP) in the applied chloroplast extracts appear to inhibit fatty acid incorporation into sn-G3P and thus to exert a regulatory function between the plastidary and extraplastidary glycerolipid biosynthesis.


1983 ◽  
Vol 61 (12) ◽  
pp. 1265-1271 ◽  
Author(s):  
R. Roy Baker ◽  
Huu-yi Chang

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.


1982 ◽  
Vol 37 (3-4) ◽  
pp. 218-225 ◽  
Author(s):  
Andreas Sauer ◽  
Klaus-Peter Heise

Abstract The aim of this investigation was to elucidate the rapid synthesis o f monogalactosyl mono­ glycerides and their role as intermediary acyl-acceptors in galactolipid synthesis of spinach chlo­ roplasts. The problem was attacked by studying the incorporation o f sn-[14C]glycerol-3-phosphate and [l-14C]acetate into the lipid fraction o f gently shocked and reconstituted preparations. The data revealed: 1 . a concurrent accumulation o f both monoglycerides and monogalactosyl monoglycerides under acidic incubation conditions, with C16-fatty acid species predominating, 2 . similarities in the fatty acid incorporation of both monoacyllipids, 3. the occurrence o f two isomeric forms viz. 1 -and 2-O-acyl-isomers o f these lipids. Thus, it appears that monogalactosyl monoglycerides are synthesized by galactosylation o f mo­ noglycerides rather than by galactolipase hydrolysis. Both monoacyllipids are likely to be derived from the corresponding lysophosphatidic acids by dephosphorylation. Their fatty acid incorporation pattern therefore may contribute to an under­ standing of the specific esterification o f different fatty acids at the Ct-and exp osition of the gly­ cerol moiety of galactolipids. Analysis o f the specific acylation o f monoglycerides and monogalac­ tosyl monoglycerides as well as the nature of the acyl donors involved in this fatty acid transfer yielded the following observations: 5. The position of the fatty acids within the monoacyllipids seems to depend on whether acyl-ACP or acyl-CoA is the primary acyl donor. 6 . The characteristics of the fatty acid incorporation into monoglycerides and their galactosylated derivatives support the notion that a successive acylation o f sn-glycerol-3-phosphate occurs first in the C2-and then in the Q-position. 7. In contrast, the chain length o f the fatty acids incorporated seems to be determined by such fac­ tors as pH and the concentration o f sn-glycerol-3-phosphate. This observation suggests that these parameters may act by controlling the elongation o f ACP-bound C16-fatty acids to their C18-species.


1959 ◽  
Vol 37 (1) ◽  
pp. 731-740 ◽  
Author(s):  
K. K. Carroll

Young male rats fed a synthetic diet containing erucic acid but lacking fat-soluble vitamins plateau at a lower weight than those fed similar diets containing no fat or other individual fatty acids. Growth resumes in the erucic acid fed rats when vitamin A acetate and corn oil are administered, but neither is effective alone. The corn oil can be replaced by methyl linoleate. Vitamin A acetate alone causes some additional growth in rats plateaued on diets containing no fat or palmitic acid but it is more effective when combined with corn oil. Rats fed an erucic acid diet containing fat-soluble vitamins still plateaued at a lower weight than rats fed a similar diet containing oleic acid.


1959 ◽  
Vol 37 (6) ◽  
pp. 731-740 ◽  
Author(s):  
K. K. Carroll

Young male rats fed a synthetic diet containing erucic acid but lacking fat-soluble vitamins plateau at a lower weight than those fed similar diets containing no fat or other individual fatty acids. Growth resumes in the erucic acid fed rats when vitamin A acetate and corn oil are administered, but neither is effective alone. The corn oil can be replaced by methyl linoleate. Vitamin A acetate alone causes some additional growth in rats plateaued on diets containing no fat or palmitic acid but it is more effective when combined with corn oil. Rats fed an erucic acid diet containing fat-soluble vitamins still plateaued at a lower weight than rats fed a similar diet containing oleic acid.


1964 ◽  
Vol 42 (1) ◽  
pp. 139-142 ◽  
Author(s):  
S. J. Patrick ◽  
L. C. Stewart

The effects of hypoglycin A on the metabolism of L-leucine-C14, L-alanine-C14, and L-glutamic-acid-C14 by rat liver slices have been investigated. Hypoglycin exerted markedly inhibitory effects on the conversion of leucine-C14 to fatty acid, cholesterol, and CO2. Conversion of alanine-C14 and glutamic acid-C14 to fatty acids was also inhibited by hypoglycin. No effects of hypoglycin on the conversion of C14-amino acids into protein or glycogen were demonstrated.


1996 ◽  
Vol 17 (2) ◽  
pp. 301-309 ◽  
Author(s):  
Sheryl K. Brining ◽  
Collins R. Jones ◽  
Michael C.J. Chang

1976 ◽  
Vol 158 (3) ◽  
pp. 593-601 ◽  
Author(s):  
P G Roughan ◽  
C R Slack ◽  
R Holland

Spinach chloroplasts, isolated by techniques yielding preparations with high O2- evolving activity, showed rates of light-dependent acetate incorporation into lipids 3-4 fold higher than any previously reported. Incorporation rates as high as 500 nmol of acetate/h per mg of chlorophyll were measured in buffered sorbitol solutions containing only NaHCO3 and [1-14C]acetate, and as high as 800 nmol/h per mg of chlorophyll when 0.13 mM-Triton X-100 was also included in the reaction media. The fatty acids synthesized were predominantly oleic (70-80% of the total fatty acid radioactivity) and palmitic (20-25%) with only minor amounts (1-5%) of linoleic acid. Linolenic acid synthesis was not detected in the system in vitro. Free fatty acids accounted for 70-90% of the radioactivity incorporated and the remainder was shared fairly evenly between 1,2-diacylglycerols and polar lipids. Oleic acid constituted 80-90% of the free fatty acids synthesized, but the diacylglycerols and polar lipids contained slightly more palmitic acid than oleic acid. Triton X-100 stimulated the synthesis of diacylglycerols 3-6 fold, but stimulated free fatty acid synthesis only 1-1.5-fold. Added glycerol 1-phosphate stimulated both the synthesis of diacylglycerols and palmitic acid relative to oleic acid, but did not increase acetate incorporation into total chloroplast lipids. CoA and ATP, when added separately, stimulated acetate incorporation into chloroplast lipids to variable extents and had no effect on the types of lipid synthesized, but when added together resulted in 34% of the incorporated acetate appearing in long-chain acyl-CoA. Pyruvate was a much less effective precursor of chloroplast fatty acids than was acetate.


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