Stearic acid unlike shorter-chain saturated fatty acids is poorly utilized for triacylglycerol synthesis and β-oxidation in cultured rat hepatocytes

Lipids ◽  
1996 ◽  
Vol 31 (2) ◽  
pp. 159-164 ◽  
Author(s):  
Tonkun Pai ◽  
Yu-Yan Yeh
2002 ◽  
Vol 2002 ◽  
pp. 206-206 ◽  
Author(s):  
Z.C.T.R. Daniel ◽  
R.J. Wynn ◽  
A.M. Salter ◽  
P.J. Buttery

Compared to meat from other animals lamb contains high levels of saturated fat, particularly stearic acid which comprises 18% of the total fatty acids (Enser et al, 1996). This stearic acid can be desaturated in the tissue by stearoyl coenzyme A desaturase (SCD) to produce oleic acid. In sheep SCD is produced from a single gene and the levels of SCD mRNA in the tissue correlate well with oleic acid (Ward et al, 1998, Barber et al, 2000) suggesting that an upregulation of SCD activity may increase the relative proportions of unsaturated and saturated fatty acids and so significantly improve the nutritional quality of sheep meat. Our recent studies have shown that insulin increases SCD mRNA levels and monounsaturated fatty acid synthesis in cultured ovine adipose tissue explants (Daniel et al, 2001). The present study was designed to investigate whether feeding a diet believed to manipulate SCD mRNA concentrations would significantly alter the fatty acid composition of lamb.


1983 ◽  
Vol 216 (1) ◽  
pp. 129-136 ◽  
Author(s):  
S L Pelech ◽  
P H Pritchard ◽  
D N Brindley ◽  
D E Vance

The influence of cyclic AMP analogues and fatty acids on glycerolipid biosynthesis in monolayer cultures of rat hepatocytes was investigated. Chlorophenylthio-cyclic AMP and adenosine 3′:5′-cyclic phosphorothioate inhibited the rate of triacylglycerol synthesis from [1(3)-3H]glycerol, and phosphatidylcholine synthesis from [Me-3H]-choline. Supplementation of the hepatocytes with palmitate (1 mM) reversed chlorophenylthio-cyclic AMP inhibition of triacylglycerol synthesis. Similarly, cyclic AMP analogue-inhibition of phosphatidylcholine synthesis was abolished when the cells were simultaneously incubated with oleate (3 mM). Reactivation of phosphatidylcholine synthesis in chlorophenylthio-cyclic AMP-supplemented cells with oleate was accompanied by conversion of CTP: phosphocholine cytidylyltransferase into the membrane-bound form, since these cells released the enzyme more slowly after treatment with digitonin. The opposing actions of cyclic AMP and fatty acids are discussed in relation to the regulation of glycerolipid biosynthesis during starvation, diabetes and stress.


1996 ◽  
Vol 316 (3) ◽  
pp. 847-852 ◽  
Author(s):  
Jennifer S. BRUCE ◽  
Andrew M. SALTER

Unlike other saturated fatty acids, dietary stearic acid does not appear to raise plasma cholesterol. The reason for this remains to be established, although it appears that it must be related to inherent differences in the metabolism of the fatty acid. In the present study, we have looked at the metabolism of palmitic acid and stearic acid, in comparison with oleic acid, by cultured hamster hepatocytes. Stearic acid was taken up more slowly and was poorly incorporated into both cellular and secreted triacylglycerol. Despite this, stearic acid stimulated the synthesis and secretion of triacylglycerol to the same extent as the other fatty acids. Incorporation into cellular phospholipid was lower for oleic acid than for palmitic acid and stearic acid. Desaturation of stearic acid, to monounsaturated fatty acid, was found to be greater than that of palmitic acid. Oleic acid produced from stearic acid was incorporated into both triacylglycerol and phospholipid, representing 13% and 6% respectively of the total after a 4 h incubation. Significant proportions of all of the fatty acids were oxidized, primarily to form ketone bodies, but by 8 h more oleic acid had been oxidized compared with palmitic acid and stearic acid.


1988 ◽  
Vol 253 (3) ◽  
pp. 693-701 ◽  
Author(s):  
D J Baisted ◽  
B S Robinson ◽  
D E Vance

The effect of albumin on the release of [3H]lysophosphatidylcholine from cultured rat hepatocytes prelabelled with [Me-3H]choline was studied. In the absence of serum and albumin from the medium, the cells released essentially no [3H]lysophosphatidylcholine. Albumin stimulated this process dramatically, and it reached a plateau at 2 mg/ml. After an initial lag of 30 min, the release of [3H]lysophosphatidylcholine was linear for at least 4 h. At low concentrations, albumin slightly stimulated [3H]phosphatidylcholine release. The albumin had no measurable effect on the metabolism of cellular [3H]phosphatidylcholine, [3H]lysophosphatidylcholine or [3H]glycerophosphocholine. In addition, albumin did not alter the release of 3H-labelled water-soluble compounds, including [3H]glycerophosphocholine, into the medium. The possibility that the [3H]lysophosphatidylcholine was arising from catabolism of [3H]phosphatidylcholine in the medium by secreted enzymes was excluded. The effect on [3H]lysophosphatidylcholine secretion was also observed when the cells were incubated with alpha-cyclodextrin, a cyclic polysaccharide that has the ability to bind lysophosphatidylcholine. The albumin-released lysophosphatidylcholine was enriched in unsaturated fatty acids. Alteration of the fatty acid composition of cellular phosphatidylcholine gave rise to parallel changes in phosphatidylcholine and lysophosphatidylcholine in the medium. It is concluded that phosphatidylcholine is constantly being degraded in the rat hepatocyte to lysophosphatidylcholine which is released into the medium only when a suitable acceptor is present.


1965 ◽  
Vol 97 (2) ◽  
pp. 371-374 ◽  
Author(s):  
JD Sink ◽  
CK Huston ◽  
JW Shigley

1. The effect of diethylstilboestrol on the fatty acid composition of adipose-tissue lipids of the ox (Bos taurus) was studied. 2. The capsula adiposa (perirenal) was shown to contain more total saturated fatty acids, whereas more total unsaturated fatty acids were found in the panniculus adiposus (subcutaneous). 3. Significantly more stearic acid and linolenic acid were obtained from the capsula adiposa, whereas the panniculus adiposus contained more myristoleic acid, palmitoleic acid and oleic acid. 4. Implanting diethylstilboestrol significantly increased the deposition of the saturated fatty acids, particularly stearic acid. 5. A decrease in the deposition of total unsaturated fatty acids, myristoleic acid, palmitoleic acid and linoleic acid can also be attributed to the diethylstilboestrol treatment.


Nutrients ◽  
2021 ◽  
Vol 13 (10) ◽  
pp. 3539
Author(s):  
Yasutake Tomata ◽  
Yunzhang Wang ◽  
Sara Hägg ◽  
Juulia Jylhävä

Background: Observational studies have suggested that fatty acids such as higher levels of n-3 polyunsaturated fatty acids (PUFAs) may prevent frailty. By using Mendelian randomization analysis, we examined the relationship between fatty acids and frailty. Methods: We used summary statistics data for single-nucleotide polymorphisms associated with plasma levels of saturated fatty acids (palmitic acid, stearic acid), mono-unsaturated fatty acids (MUFAs) (palmitoleic acid, oleic acid), n-6 PUFAs (linoleic acid, arachidonic acid), and n-3 PUFAs (alpha-linolenic acid, eicosapentaenoic acid, docosapentaenoic acid, docosahexaenoic acid), and the corresponding data for frailty index (FI) in 356,432 individuals in the UK Biobank. Results: Although there were no robust associations on the MUFAs or the PUFAs, genetically predicted higher plasma stearic acid level (one of saturated fatty acids) was statistically significantly associated with higher FI (β = 0.178; 95% confidence interval = −0.050 to 0.307; p = 0.007). Such a relationship was also observed in a multivariate MR (β = 0.361; 95% confidence interval = 0.155 to 0.567; p = 0.001). Genetically predicted higher palmitic acid was also significantly associated with higher FI (β = 0.288; 95% confidence interval = 0.128 to 0.447; p < 0.001) in the multivariate MR analysis. Conclusions: The present MR study implies that saturated fatty acids, especially stearic acid, is a risk factor of frailty.


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