Lack of effect of captopril on the metabolism of an artificial lipid emulsion similar to chylomicrons in hypertensive hypercholesterolemic patients.

Objective: To assess the effect of captopril, an angiotensin-converting enzyme inhibitor, on the metabolism of chylomicrons and their remnants and the possible alterations in the concentrations of plasma lipids caused by the drug in hypertensive hypercholesterolemic individuals.

Methods: The metabolism of chylomicrons was tested with the method of artificial lipid emulsion of chylomicrons labeled with 3H-cholesteryl oleate. The emulsion was injected intravenously in 10 patients with mild-moderate arterial hypertension before and 45 days after treatment with captopril (50 mg/day).

Metabolism of chylomicrons in patients with congenital lipoatrophic diabetes: a study with emulsion models of chylomicrons.

Background: Lipoatrophic diabetes is characterized by the near absence of adipose tissue and the presence of insulin-resistant diabetes. Fasting hypertriglyceridaemia and increased postprandial lipidaemia are also present, but the metabolism of chylomicrons, the triglyceride-rich lipoproteins in the circulation that carry the dietary fats absorbed by the intestine, was not specifically investigated. Because both the activity of insulin-dependent lipoprotein lipase that catalyses the chylomicron lipolysis and the storage of the lipolysis products are affected in the disease, it is important to evaluate how those changes may ultimately affect the chylomicron lipolysis and removal of chylomicron remnants from the circulation.

Clearance of a 3H-labeled chylomicron-like emulsion following the acute phase of myocardial infarction.

Background: Plasma lipids may be altered during acute myocardial infarction and may not reflect patient baseline lipid profile. The metabolism of chylomicrons, the lipoproteins that carry the dietary lipids in the bloodstream has not yet been studied in acute myocardial infarction patients.

Methods: In this study, a lipidic emulsion that mimics the intravascular behavior of chylomicrons labeled with cholesteryl oleate ((3)H-CO) was injected intravenously in 17 normolipidemic patients on the seventh and on the 45th day post-non complicated acute myocardial infarction after a 12-h fast.

Metabolism of chylomicron-like emulsions in carriers of the S447X lipoprotein lipase polymorphism.

Background: Lipoprotein lipase catalyzes the hydrolysis of the triglycerides contained in both very-low-density lipoproteins and chylomicrons for storage in the adipose tissue and muscle of fats of both hepatic and dietary origin. The S447X-Stop lipoprotein lipase is the most common polymorphism of the enzyme, affecting roughly 20% of the population and is accompanied by normal or diminished fasting triglycerides and perhaps lower incidence of coronary artery disease (CAD). Delay in the removal of chylomicron and remnant is now an established risk factor for CAD.

Atorvastatin enhances the plasma clearance of chylomicron-like emulsions in subjects with atherogenic dyslipidemia: relevance to the in vivo metabolism of triglyceride-rich lipoproteins.

Delayed chylomicron clearance is a characteristic of patients with coronary artery disease. In vivo study of the clearance of labeled chylomicron-like emulsions constitutes a valid model system for evaluation of chylomicron catabolism. The effects of atorvastatin at low (10 mg) and high (40 mg) dose upon the intravascular metabolism and plasma kinetics of chylomicron-like emulsions were evaluated in fasting hyperlipidemic subjects (n=45).

Uptake of a cholesterol-rich emulsion by breast cancer.

Objective: Overexpression of low-density lipoprotein (LDL) receptors occurs in several cancer cell lines and offers a unique strategy for drug targeting by using LDL as vehicle. However, the native lipoprotein is difficult to obtain and handle. Previously, we showed that a lipidic emulsion (LDE) similar to the lipid structure of native LDL may bind to LDL receptors and be taken up by acute myelocytic leukemia cells.