The in vitro formation of HDL2 during the action of LCAT: the role of triglyceride-rich lipoproteins.

We examined the effects of lecithin:cholesterol acyl transferase (LCAT) and of lipoprotein lipase (LPL) on the conversion of high density lipoproteins (HDL) towards fractions of lower densities using the analytical ultracentrifuge. Freshly isolated whole plasma was incubated for 24 h at 37 degrees C in the presence or absence of active enzyme systems. In some cases, lipoproteins were removed by selective precipitations; alternatively, we added triglyceride-rich lipoproteins (TGRLP) or Intralipid to the incubations.

The interaction of human plasma low density lipoproteins with glycosamino-glycans: influence of the chemical composition.

Human plasma of 5 normolipemic individuals was incubated for 24 hr at 37 C in the presence or in the absence of lecithin:cholesterol acyltransferase (LCAT)-inhibitors. Plasma stored at 4 C served as a control. The low density lipoprotein (LDL) fractions of the samples were isolated and investigated with respect to changes in chemical composition and complexing activity with glycosamino glycans (GAG).

Plasma lipids and lipoproteins of a patient with cholesteryl ester storage disease.

The plasma lipids, lipoproteins and lipolytic enzymes of a patient suffering from cholesterol ester storage disease were investigated and followed over a time period of 3 years. The patient was hypertriglyceridaemic and cholesterolaemic and exhibited very low levels of high density lipoproteins. These lipoproteins consisted almost exclusively of the HDL-subfraction-3.

In vitro modification of the chemical composition of human plasma low density lipoproteins: effects of morphology and thermal properties.

The effects of enzymatic action on human low density lipoproteins (LDL) occurring during in vitro incubation of plasma have been studied by chemical analysis, analytical ultracentrifugation, negative stain electron microscopy and X-ray small angle scattering. Chemically, the action of cholesteryl ester exchange and transfer proteins(s) (CEPT) leads to a relative increase in trigylcerides at the expense of cholesteryl esters. Morphologically, the particles maintain their characteristic features detectable by X-ray small angel scattering.

The low-density-lipoprotein pathway of native and chemically modified low-density lipoproteins isolated from plasma incubated in vitro.

Normal fasting human plasma was incubated for 24 h at 37 degrees C in the presence or absence of lecithin:cholesterol acyltransferase (LCAT) inhibitors. The low-density lipoprotein (LDL) fractions of incubated plasma (control LDL and LCAT-modified LDL) were studied with respect to their chemical and functional properties. LCAT-modified LDL differed from control LDL by a decreased phospholipid and free-cholesterol content, but increased cholesteryl esters.

Isolation and characterization of polymorphic forms of porcine apoC-II by chromatofocusing.

Chromatofocusing, which separates proteins on the basis of their different isoelectric points, was used to isolate isoforms of apoC-II from porcine very low density lipoproteins. This method was found to be time-saving and the yield of protein recovery was high. With chromatofocusing, three polypeptides were obtained which were characterized by amino acid analysis, double immunodiffusion, and by their ability to activate bovine milk lipoprotein lipase.

Effect of bezafibrate on plasma lipids, lipoproteins, apolipoproteins AI, AII and B and LCAT activity in hyperlipidemic, non-insulin-dependent diabetics.

The effect of bezafibrate on plasma lipids, lipoproteins, apolipoproteins AI, AII and B, and LCAT activity was investigated in 16 hyperlipidemic, non-insulin-dependent diabetes, who were treated for 8 weeks with either placebo or bezafibrate in a double-blind cross-over design. Bezafibrate induced a significant decrease in plasma triglycerides (P less than 0.01), cholesterol (P less than 0.