triolein and Coronary-Artery-Disease

The atherogenic role of a delayed intravascular catabolism of chylomicrons has been suggested by univariate analysis of case-control studies. However, it is not established whether this association is caused by a direct atherogenic effect of these lipoproteins or results from the presence of concurrent and metabolically-related coronary artery disease (CAD) risk factors. In this study, the plasma kinetics of a chylomicron-like emulsion doubly labeled with 14C-cholesteryl oleate (CE) and 3H-triolein (TG) was determined in 93 subjects with or without angiographically-defined CAD. As compared with controls and even after adjustment for body mass index (BMI), LDL- and HDL-cholesterol, and the presence of traditional risk factors, CAD patients had 45% smaller fractional clearance rate (FCR) of TG, 41% smaller FCR-CE and 19% smaller dilapidation index (DI; P < 0.05). Among CAD patients, those with highest angiographic score had 66% smaller FCR-TG (P = 0.007), 50% smaller FCR-CE (P = 0.01) and 27% smaller DI (P = 0.004). In a multivariate logistic regression analysis, FCR-CE (P < 0.0001) and DI (P = 0.001) were the only independent predictors for the presence of CAD. In conclusion, we presently show that the rate of lipolysis and removal from the circulation of chylomicron-like emulsions constitutes an independent predictor of CAD and a marker of CAD severity.

Topics: Adult; Aged; Body Mass Index; Carbon Radioisotopes; Case-Control Studies; Cholesterol Esters; Chylomicrons; Coronary Angiography; Coronary Artery Disease; Emulsions; Female; Humans; Kinetics; Lipoproteins; Male; Middle Aged; Multivariate Analysis; Predictive Value of Tests; Prognosis; Triolein

It has been generally accepted that oxidized low density lipoprotein (LDL) plays an important role in atherogenesis. However, oxidized LDL was not detected in patients' blood and the extent of LDL oxidation in vivo is unknown. We have suggested that LDL oxidation may lead to a formation of covalent links between lipids and apolipoprotein B. LDL were oxidized by copper ions, 2,2'-azobis-(2-aminopropane hydrochloride), sodium hypochlorite or by incubation with macrophages. Oxidized LDL were delipidated by repeated extraction with organic solvents. After mild alkaline hydrolysis protein-bound sterols were identified colorimetrically and by high-performance liquid chromatography. Protein-bound phospholipid residues were detected by nuclear magnetic resonance and colorimetric determination of phosphate. Using radiolabeled lipids it was also shown that free and esterified cholesterol, phospholipids, as well as triglyceride and free fatty acid residues can form covalent bonds with apolipoprotein B. The ability of lipids to bind to apolipoprotein B correlates with the degree of unsaturation of their fatty acids and depends on the nature of polar head of phospholipids. When LDL were oxidized with copper ions, the content of protein-bound lipids increased gradually up to 24 h of incubation, while the levels of conjugated dienes, hydroperoxides and thiobarbituric acid-reactive substances changed in varying manners. It has been demonstrated that the content of protein-bound sterols in multiple-modified desialylated LDL of patients with coronary atherosclerosis is higher than that in native LDL. Our results suggest that the level of protein-bound lipids may be a marker of LDL oxidation and can be used to evaluate the association of lipoprotein oxidation and atherogenesis.

Topics: Adult; Apolipoproteins B; Biomarkers; Cholesterol; Cholesterol Esters; Coronary Artery Disease; Female; Humans; Kinetics; Lipoproteins, LDL; Male; Middle Aged; Oleic Acid; Oleic Acids; Oxidation-Reduction; Phospholipids; Protein Binding; Reference Values; Thiobarbituric Acid Reactive Substances; Triolein

The value of the oral triolein-I(131) "tolerance" test in the study of patients with coronary heart disease was assessed. Thirtynine patients were divided into three groups: those with clinical evidence of coronary heart disease, those with increased risk, and those with no increased risk of coronary heart disease. The variability of the results precluded differentiation between the groups on the basis of this test. A minority of the patients with coronary heart disease showed strikingly elevated blood levels of lipid-bound radioactivity following the oral ingestion of triolein-I(131). It was concluded that this test is of no use in the diagnosis of coronary heart disease but may identify those patients with coronary heart disease who dispose of orally ingested fat in a grossly abnormal fashion.

Topics: Coronary Artery Disease; Coronary Disease; Dietary Fats; Humans; Iodine Isotopes; Lipid Metabolism; Lipids; Radioisotopes; Radionuclide Imaging; Triolein

Topics: Coronary Artery Disease; Coronary Disease; Humans; Iodine Isotopes; Lipid Metabolism; Triolein

Topics: Arteriosclerosis; Coronary Artery Disease; Coronary Disease; Iodine Isotopes; Lipid Metabolism; Lipids; Oils; Triolein

Topics: Arteries; Coronary Artery Disease; Coronary Disease; Humans; Triolein

Topics: Coronary Artery Disease; Coronary Disease; Humans; In Vitro Techniques; Iodine Isotopes; Myocardial Infarction; Triolein

Topics: Coronary Artery Disease; Coronary Disease; Iodine Isotopes; Lipid Metabolism; Triolein

Topics: Aged; Coronary Artery Disease; Coronary Disease; Fats, Unsaturated; Heart; Humans; Metabolic Diseases; Triolein