High levels of high-density lipoprotein (HDL) cholesterol have been reported to protect against the development of atherosclerosis in humans by increasing reverse cholesterol transport and inhibiting the oxidation of low-density lipoprotein (LDL) due to the paraoxonase content of HDL. The purpose of the present study was to assess if there are any relationships between in vivo increases in seru...

we studied the effect of different concentrations of alpha-tocopherol on in vitro cupric ions induced oxidation of low density lipoproteins (ldl). human native ldl (50 µg protein/ml) oxidation was induced by 10 µmol/l of cuso4. conjugated dienes were measured spectrophotometrically for up to 440 minutes. the length of the lag phase (tlag), maximum velocity of the reaction (vmax) and the maximum...

The regulation of macrophage lipoprotein lipase (LPL) secretion and mRNA expression by atherogenic lipoproteins is of critical relevance to foam cell formation. LPL is present in arterial lesions and constitutes a bridging ligand between lipoproteins, proteoglycans, and cell receptors, thus favoring macrophage lipoprotein uptake and lipid accumulation. We investigated the effects of native and ...

Hypothyroidism leads to an increase of plasma low-density lipoprotein (LDL) cholesterol levels. Oxidation of LDL particles changes their intrinsic properties, thereby enhancing the development of atherosclerosis. T4 has three specific binding sites on apolipoprotein B; furthermore it inhibits LDL oxidation in vitro. We therefore hypothesized that T4 deficiency not only results in elevated LDL-c...

A theoretical model is presented that explains slow copper-induced oxidation of low-density lipoprotein in the systems free of seeded hydroperoxydes. The model is based on the probabilistic kinetic theory, modified to take into account different radical generation rates by oxidized and reduced forms of the metal ions. It is shown that the initiation and progression of the LDL oxidation can take...

BACKGROUND Oxidative modification of low-density lipoprotein (LDL) appears to be an early step in the pathogenesis of atherosclerosis. Meanwhile, myeloperoxidase (MPO)-catalyzed reaction is one of the potent pathway for LDL oxidation in vivo. The aim of this study was to evaluate in vitro antioxidant effects of vitamins C and E on LDL oxidation mediated by MPO. METHODS MPO was isolated from f...

The reversible interaction of low density lipoprotein (LDL) with arterial chondroitin sulfate proteoglycans (CSPGs) or glycosaminoglycans (GAGs) selects LDL particles with a high affinity for sulfated GAGs and also induces modifications in apolipoprotein B (apo B) and the lipid organization of the lipoprotein. In the present work we studied the effect that the reversible interaction with sulfat...

There is relatively little information on the role of high density lipoprotein (HDL) oxidation in atherogenesis although there are indications that oxidation might affect atheroprotective activities of HDL. Recently we reported the study on LDL oxidation initiated and sustained by traces of the transition metal ions under conditions, which favor slow oxidation. Here we report the results of the...

The oxidative modification of low density lipoprotein (LDL) may play an important role in atherogenesis. Antioxidants that can prevent LDL oxidation may act as antiatherogens. Our understanding of the mechanism of LDL oxidation and factors that determine its susceptibility to oxidation is still incomplete. Copper is a candidate for oxidizing LDL in atherosclerotic lesions. The binding of copper...

Hypothyroidism is frequently associated with hypercholesterolemia and an increased risk for atherosclerosis, whereas hyperthyroidism is known to precipitate angina or myocardial infarction in patients with underlying coronary heart disease. We have shown previously that L-T4 functions as an antioxidant in vitro and inhibits low density lipoprotein (LDL) oxidation in a dose-dependent fashion. Th...