Distribution of apolipoprotein A-IV among lipoprotein subclasses in rat serum.

The distribution of apolipoproteins (apo) A-I, A-IV, and E in sera of fed and fasted rats was studied using various methods for the isolation of lipoproteins. Serum concentrations of apoA-I and apoA-IV decreased significantly during fasting (16 and 31%, respectively), while apoE concentrations remained essentially the same. Chromatography of sera on 6% agarose columns showed that apoA-IV is present on HDL and as so-called "free" apoA-IV.

Electroimmunoassay of rat apolipoproteins A-I, A-IV, and E. A procedure for sample treatment to increase the sensitivity in diluted fractions.

Methods for the quantitative determination of rat apolipoproteins A-I, A-IV, and E by electroimmunoassay are described. Apolipoproteins present in diluted samples of biological fluids (approx. 2 ml) were concentrated by precipitation with deoxycholate and trichloroacetic acid.

Leupeptin as a tool for the detection of the sites of catabolism of rat high-density lipoprotein apolipoproteins A-I and E.

Leupeptin, an inhibitor of lysosomal cathepsin activity, was injected intravenously into male rats. Tissues obtained from leupeptin-treated animals showed a depressed cathepsin activity when compared with tissues from saline-treated control animals. Leupeptin treatment did not change the hepatic activities and subcellular distribution of marker enzymes for mitochondria, microsomes and plasma membranes.

Separation of rat plasma HDL subfractions by density gradient centrifugation and the effect of incubation on these fractions.

The conditions for the separation of rat high density lipoproteins (HDL) in a single ultracentrifuge run are described. By this method six serum samples can be processed simultaneously. HDL is separated into two main fractions, one with apolipoprotein E and the other with apolipoprotein A-I as the major protein component.

Effects of amount and type of dietary fat on serum lipids, lipoproteins and apolipoproteins in man. A controlled 8-week trial.

We have studied whether a low-fat diet is as effective in lowering some risk factors for atherosclerosis as a diet rich in polyunsaturated fat (PUFA). During a 2.5 week control period, 60 volunteers were given a moderate-fat diet (MOD) providing 30% of the daily energy intake (energy %) in the form of fat, one-third of which was PUFA.

Dependence of the effects of dietary cholesterol and experimental conditions on serum lipids in man. III. The effect on serum cholesterol of removal of eggs from the diet of free-living habitually egg-eating people.

Forty-four healthy free living volunteers were used to study the effect of the removal of eggs from a habitual egg-rich diet. The subjects, recruited by advertising, normally consumed at least 1 egg per day. During the 3-week experimental period they were not allowed to eat any eggs or products containing large amounts of eggs, except cakes and tarts.