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Biomedical subjects

M Naruszewicz

Publications and source records attributed to M Naruszewicz.

60 records · Page 4Linked to original sources
PubMedDate not supplied

Propranolol decreases cholesteryl ester accumulation in mouse peritoneal macrophage in vitro.

Current evidence indicates that the non-selective beta-blocker propranolol reduces the severity of experimental atherosclerosis in animal model. We studied the effect of propranolol on cholesterol ester synthesis and storage in mouse peritoneal macrophages in vitro. Propranolol in concentrations found in the plasma of patients treated with it (150 ng/ml) decreased by 20-30% beta-VLDL-stimulated synthesis of cholesterol esters with (14C)-oleate. A similar effect was observed also on this synthesis stimulated by acetyl-LDL. In a similar degree the accumulation of cholesteryl esters in the cells was decreased during the 48-hour incubation with lipoproteins in the presence of propranolol. No effect of the drug was observed on the uptake and degradation of beta-VLDL or acetyl-LDL. These observations suggest that propranolol may inhibit cholesteryl ester accumulation in macrophages at the point subsequent to lipoprotein uptake. This may have an impact on the treatment or prevention of atherosclerosis.

Animals↗
PubMedDate not supplied

Influence of experimental diets on cholesterol and triglyceride levels of rabbit blood serum lipoproteins.

Groups of rabbits were fed for six weeks various diets: standard died + ethanol, high-cholesterol diet and a high-cholesterol + ethanol one. During the next six weeks every diet was supplemented with a fresh vegetable (carrot). Cholesterol and triglycerides were determined in the whole serum and in lipoprotein fractions. In rabbits fed standard diet ethanol caused a moderate elevation of VLDL cholesterol and triglyceride and LDL cholesterol levels. In animals on high-cholesterol diet cholesterol and triglyceride concentrations in these fractions were very high. Simultaneous consumption of large amounts of cholesterol and of ethanol resulted in a greater rise of cholesterol concentration in the whole serum and in VLDL and LDL fraction than did high-cholesterol diet alone. Addition of carrot caused a pronounced reduction of serum cholesterol concentration in animals fed all kinds of diets. The reduction concerned mainly VLDL.

Animals↗
PubMedDate not supplied

Lipoprotein fractions in idiopathic hyperlipoproteinaemia.

The purpose of the study was an assessment of the lipid and protein composition of very low density lipoproteins (VLDL) in hyperlipoproteinaemias type IIa, IIb, III and IV. Besides that, cholesterol was determined in low density lipoproteins (LDL) and high density lipoproteins (HDL). Fifty-seven patients with idiopathic hyperlipoproteinaemia and nineteen subjects without lipid metabolism disturbances were studied. The VLDL fraction was obtained by ultracentrifugation of the serum. The LDL and HDL fractions were separated by precipitation. A raised value of the LDL:HDL cholesterol ratio was found in hyperlipoproteinaemias type IIb, III and IV. Positive correlations between the concentrations of lipid and protein components of the VLDL fraction were found in hyperlipoproteinaemias type IIa, IIb, IV and in normolipaemia, which suggests maintained proportions between VLDL components. The high proportion of cholesterol in the VLDL fraction in relation to other components in type III hyperlipoproteinaemia indicates an abnormal composition of this fraction.

Cholesterol↗
PubMedDate not supplied

Apolipoproteins C in very low density lipoproteins (VLDL) in idiopathic hyperlipoproteinaemia.

The purpose of this study was an assessment of the relative proportions of apolipoprotein C subfractions in the VLDL fraction, which could contribute to explaining the development of metabolic disturbances in hyper-pre-beta-lipoproteinaemias. The study was carried out in 21 patients with hyperlipoproteinaemia type IIa, IIb, III, IV and in 8 subjects without lipid metabolism disturbances. Apolipoproteins C were separated in disc electrophoresis on polyacrylamide gel (PAGE) with added 8-M of urea. After the electrophoresis three main subfractions were obtained and were identified according to their electrophoretic mobility as Apo CII, Apo CIII1 and Apo CIII2. The relative per cent proportions of apolipoproteins C were determined by densitometry. A correlation was found between triglyceride concentration in the VLDL fraction and the relative amounts of Apo CII and Apo CIII1. Moreover, a raised ratio of the lipoprotein lipase inhibitor (Apo CIII1) to the activator of this enzyme (Apo CII) was demonstrated in hyperlipoproteinaemias type IIb, III and IV, which may suggest decreased susceptibility of these lipoproteins to the action of lipoprotein lipase.

Apolipoproteins↗