scholarly journals Effects of polyunsaturated fatty acids and/or lecithin on the plasma concentrations of very low density lipoprotein-tryglyceride(VLDL) and ketone bodies in humans.

1988 ◽  
Vol 35 (2) ◽  
pp. 71-76
Author(s):  
SHIGERU KURINAMI ◽  
NAOKO KUMAGAI ◽  
HIDEKI HAYASHI ◽  
YOSHIKO HAYASHIDA ◽  
MASAYUKI SATO ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Polyunsaturated Fatty Acids ◽  
Ketone Bodies ◽  
Low Density Lipoprotein ◽  
Plasma Concentrations ◽  
Density Lipoprotein ◽  
Very Low Density Lipoprotein ◽  
Low Density

Comparison of the effects of dietary n−3 and n−6 polyunsaturated fatty acids on very-low-density lipoprotein secretion when delivered to hepatocytes in chylomicron remnants

2001 ◽  
Vol 357 (2) ◽  
pp. 481-487 ◽  
Author(s):  
Xiaozhong ZHENG ◽  
Michael AVELLA ◽  
Kathleen M. BOTHAM
Keyword(s):  
Fatty Acids ◽  
Polyunsaturated Fatty Acids ◽  
Fish Oil ◽  
Corn Oil ◽  
Low Density Lipoprotein ◽  
Density Lipoprotein ◽  
Very Low Density Lipoprotein ◽  
Low Density ◽  
Chylomicron Remnants

The effects of chylomicron remnants enriched in n-3 or n-6 polyunsaturated fatty acids (derived from fish or corn oil respectively) on the secretion of very-low-density lipoprotein (VLDL) lipid and apolipoprotein B (apoB) by rat hepatocytes in culture was investigated. Remnants were prepared in vivo from chylomicrons obtained from rats given an oral dose of fish or corn oil and incubated with cultured hepatocytes for up to 16h. The medium was then removed and the secretion of cholesterol and triacylglycerol into the whole medium or the ρ < 1.050g/ml fraction during the following 7–24h was determined. After exposure of the cells to fish-oil as compared with corn-oil remnants, secretion of both cholesterol and triacylglycerol into the whole medium was decreased by 25–35%, and secretion into the ρ < 1.050g/ml fraction was decreased by 20–25%. In addition, the levels of apoB48 found in the ρ < 1.050g/ml fraction were significantly lower in cells treated with fish-oil rather than corn-oil remnants, although the levels of apoB100 remained unchanged. The expression of mRNA for apoB, as determined by reverse-transcriptase PCR, however, was not significantly changed after exposure of the cells to both types of remnants. These results demonstrate that the effects of dietary n-3 polyunsaturated fatty acids in depressing hepatic VLDL secretion occur directly when they are delivered to the liver from the intestine in chylomicron remnants, and that the secretion, but not the synthesis, of apoB is targeted.

Comparison of the effects of dietary saturated, mono-unsaturated and polyunsaturated fatty acids on very-low-density lipoprotein secretion when delivered to hepatocytes in chylomicron remnant-like particles

2007 ◽  
Vol 35 (3) ◽  
pp. 440-441 ◽  
Author(s):  
I. Lopez-Soldado ◽  
M. Avella ◽  
K.M. Botham
Keyword(s):  
Fatty Acids ◽  
Polyunsaturated Fatty Acids ◽  
Olive Oil ◽  
Corn Oil ◽  
Low Density Lipoprotein ◽  
Density Lipoprotein ◽  
Rat Hepatocytes ◽  
Very Low Density Lipoprotein ◽  
Low Density ◽  
Chylomicron Remnant

The effect of chylomicron remnant-like particles (CRLPs) enriched in saturated, mono-unsaturated or n−6 polyunsaturated fatty acids (derived from palm, olive or corn oil, respectively) on the secretion of VLDL (very-low-density lipoprotein) by rat hepatocytes in culture was investigated. CRLPs were incubated with cultured hepatocytes for 5 h. The medium was then removed and the secretion of cholesterol and triacylglycerol (TAG) into the whole medium during the following 16 h was determined. After exposure of the cells to olive oil as compared with corn and palm oil CRLPs, secretion of TAG into the medium was decreased. The TAG content of the cells was also lower in experiments with olive oil as compared with corn oil CRLPs. The levels of apoB48 (apolipoprotein B48) found in the medium remained unchanged after the exposure of the cells to the different types of remnants. These findings indicate that the type of fat in the diet directly affects VLDL lipid secretion on delivery to the liver in chylomicron remnants.

scholarly journals The lipolysis/esterification cycle of hepatic triacylglycerol. Its role in the secretion of very-low-density lipoprotein and its response to hormones and sulphonylureas

1992 ◽  
Vol 284 (2) ◽  
pp. 457-462 ◽  
Author(s):  
D Wiggins ◽  
G F Gibbons
Keyword(s):  
Fatty Acids ◽  
Low Density Lipoprotein ◽  
Density Lipoprotein ◽  
Very Low Density Lipoprotein ◽  
Low Density ◽  
Intracellular Pool ◽  
Hepatocyte Cultures ◽  
Vldl Secretion ◽  
Vldl Assembly ◽  
Hepatic Triacylglycerol

In hepatocyte cultures maintained in the absence of extracellular fatty acids, at least 70% of the secreted very-low-density lipoprotein (VLDL) triacylglycerol was derived via lipolysis of intracellular triacylglycerol. This proportion was unchanged when the cells were exposed for 24 h to insulin or glucagon, hormones which decreased the overall secretion of intracellular triacylglycerol, or to chloroquine or tolbutamide, agents which inhibit lysosomal lipolysis. The rate of intracellular lipolysis was 2-3-fold greater than that required to maintain the observed rate of triacylglycerol secretion. Most of the fatty acids released were returned to the intracellular pool. Neither insulin nor glucagon had any significant effect on the overall lipolysis and re-esterification of intracellular triacylglycerol. In these cases a greater proportion of the released fatty acids re-entered the cellular pool, rather than being recruited for VLDL assembly. Tolbutamide inhibited intracellular lipolysis, but suppressed VLDL secretion to a greater extent. 3,5-Dimethylpyrazole did not affect lipolysis or VLDL secretion. The increased secretion of VLDL triacylglycerol observed after exposure of cells to insulin for 3 days was not accompanied by an increased rate of intracellular lipolysis. However, a larger proportion of the triacylglycerol secreted under these conditions may not have undergone prior lipolysis.

scholarly journals Electronic and Tobacco Cigarettes Alter Polyunsaturated Fatty Acids and Oxidative Biomarkers

2021 ◽  
Author(s):  
Rajat Gupta ◽  
Yan Lin ◽  
Karla Luna ◽  
Anjali Logue ◽  
Alexander J Yoon ◽  
...  
Keyword(s):  
Lipid Peroxidation ◽  
Fatty Acids ◽  
Cardiovascular Risk ◽  
Polyunsaturated Fatty Acids ◽  
Low Density Lipoprotein ◽  
Plasma Concentrations ◽  
Multivariable Analysis ◽  
Plasma Lipid ◽  
Density Lipoprotein ◽  
Heme Oxygenase 1

Rationale: Chronic electronic cigarette (EC) users exhibit a higher susceptibility of low-density lipoprotein (LDL) to undergo oxidation as compared to non-user controls. However, there is a paucity of data regarding EC effects on lipid peroxidation in the blood and their relationship to cardiovascular risk. Objective: To test the hypothesis that chronic (≥1 year) EC use exerts intermediate effects on plasma lipid peroxidation and/or antioxidant defense compared to chronic tobacco cigarette (TC) smoking. Methods and Results: We enrolled EC-users (n=32), TC-smokers (n=29) and non-users (n=45), with mean ages of 28.3, 27.8 and 27.4 years, respectively. Plasma concentrations of free polyunsaturated fatty acids and oxidized metabolites were assessed by mass spectrometry. Total antioxidant capacity (TAC), concentrations of glutathione, bilirubin, heme oxygenase-1 (HO-1), and functional activity of paraoxonase1 (PON1) were determined by colorimetric and enzymatic assays. Multivariable analysis was performed using classification models for segregating participants based on biomarker profiles. Plasma arachidonic acid (AA) concentration was higher in TC-smokers but lower in EC-users, together with linoleic acid (LA) concentration, as compared to TC-smokers and non-users (p<0.05). Oxidized LA metabolites (9- and 13-hydroxyoctadecadienoic acid (HODE)) were lower in EC-users and TC-smokers as compared to non-users (p<0.001). Consistently, TAC and bilirubin were elevated in EC-users and TC-smokers as compared to non-users (p<0.05). Of interest, plasma HO-1 concentration was higher in TC-smokers as compared to non-users (p=0.01) with intermediate levels in EC-users. Multivariable analysis identified 5 biomarkers (13-HODE, LA, 9-HODE, 12-hydroxyeicosatetraenoic acid (HETE), AA) that discriminated EC-users from TC-smokers and non-users with an accuracy of 73.4%. Conclusions: Chronic use of EC induces common (i.e. lower 9- and/or 13-HODEs and higher TAC and bilirubin) as well as differential effects (i.e. altered AA and LA concentrations) to those induced by TC, along with intermediate plasma HO-1 concentration, suggesting that EC, likewise TC smoke, could impact cardiovascular risk.

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