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M Nibbelink

Publications and source records attributed to M Nibbelink.

27 records · Page 2Linked to original sources
PubMed1985

Effect of dietary restriction on the plasma apolipoprotein pattern in cholesterol-fed rabbits.

Dietary restriction (half of the control ration) was performed in rabbits given either standard or cholesterol-rich diets. The plasma apolipoproteins were studied on the total, d less than 1.21, lipoprotein fraction using polyacrylamide gel electrophoresis. A marked rise in the amount of both apo-B and apo-E appeared in cholesterol-fed rabbits and was enhanced by dietary restriction. These results reflect the aggravation of hypercholesterolemia when cholesterol feeding is carried out in underfed rabbits. In all groups only one molecular species of apo-B, identified as apo-B-100, was present after overnight fasting. Thus, lipoproteins which accumulate in the plasma following cholesterol feeding, associated with dietary restriction or not, probably are remnants of hepatogenous triglyceride-rich lipoproteins.

Animals↗
PubMed1985

Effect of dietary restriction on cholesterol biosynthesis in the liver and the intestine of cholesterol-fed rabbits.

The effect of dietary restriction (half of the control ration) on cholesterol biosynthesis was investigated in rabbits fed either standard or cholesterol-rich diets. Accompanying the amplification of hypercholesterolemia, additional disturbances of cholesterol metabolism were observed when cholesterol feeding was associated with dietary restriction. In the intestine, underfed rabbits showed a more marked inhibition of duodenal cholesterol biosynthesis from [14C]acetate following cholesterol feeding than rabbits on normal caloric ration. In contrast liver cholesterogenesis was equally suppressed in both groups receiving cholesterol-rich diets. Cholesterol biosynthesis from [14C]mevalonate was also inhibited by cholesterol feeding particularly in the duodenum of underfed rabbits. In addition cholesterol feeding induced a marked increase of the labeled esterified: free cholesterol ratio in the liver, demonstrating intensive esterification, this was enhanced by dietary restriction. The additional cholesterol which accumulates in the plasma and in various tissues in underfed rabbits is of dietary origin since the feedback control of cholesterogenesis by exogenous cholesterol was shown to be very effective in these animals.

Animals↗
PubMed1984

Influence of cholesterol feeding and dietary restriction on cholesterol absorption in rabbits.

Plasma cholesterol and cholesterol absorption were measured in rabbits given either a standard or cholesterol-rich diet which were fed either ad libitum or reduced to 50% of the control ration. The results confirmed the aggravating effect of dietary restriction on the plasma cholesterol response to cholesterol feeding. Hypercholesterolemia was doubled when cholesterol feeding was associated with reduced dietary intake. The percentage of cholesterol absorbed increased significantly in cholesterol-fed rabbits on normal caloric ration, while dietary restriction had no effect on this parameter either with the standard or the cholesterol-rich diet. These data indicate that the mechanisms by which plasma cholesterol increases in response to cholesterol feeding involve increased cholesterol absorption. Nevertheless the aggravating effect of dietary restriction cannot be attributed to increased cholesterol absorption.

Animals↗
PubMed1983

Increases in hyperlipoproteinemia, disturbances in cholesterol metabolism and atherosclerosis induced by dietary restriction in rabbits fed a cholesterol-rich diet.

The influence of dietary restriction on cholesterol transport and metabolism was investigated in rabbits given standard or cholesterol-rich diets (0.2 g cholesterol/kg body weight daily) either ad libitum or with 50% caloric ration. Dietary restriction which has only a slight influence in control rabbits markedly aggravated the disturbances induced by exogenous cholesterol. With limited feeding, control rabbits presented a moderate increase in plasma cholesterol, whereas marked aggravation of hypercholesterolemia was observed in cholesterol-fed rabbits. Analysis of the lipoprotein profile showed that the excess of plasma cholesterol with the restricted cholesterol-rich diet corresponded to an increase in the concentration of very low density lipoprotein (VLDL) and low density lipoproteins (LDL) without any additional changes in the composition of these lipoproteins. No significant change appeared in the high density lipoprotein (HDL) concentration. The parameters of cholesterol metabolism were determined, from the curves of [3H]cholesterol radioactivity decrease, using a two-pool model. The increase in cholesterol turnover rate induced by the cholesterol-rich diet was accentuated by dietary restriction, whereas rabbits on standard restricted diet showed a slight decrease. The large increase in the size of both pools A and B in cholesterol-fed rabbits was even more pronounced with limited feeding. Dietary restriction induced additional accumulation of cholesterol in the aortic wall and the grade of the lesions was also aggravated.

Animals↗
PubMed1983

[The effect of insulin on hyperlipoproteinemia induced by a semi-synthetic diet rich in saturated fats in a rabbit].

The influence of insulin therapy on changes in the lipoprotein profile induced by a semi-synthetic saturated-fat diet was studied in the rabbit. Hypercholesterolemia, observed after two months diet, corresponded to an increase in all lipoprotein fractions as well as an enrichment in cholesterol esters of VLDL and LDL. Treatment with insulin had only a slight effect on the increase in the lipoproteins, but completely prevented the appearance of abnormal LDL. Changes in the lipoprotein profile were markedly aggravated, without an additional increase in plasma cholesterol, when the semi-synthetic diet was continued for six months. All lipoprotein fractions showed increases in cholesterol esters and in free cholesterol at the expense of triglycerides and proteins. The animals receiving the semi-synthetic diet and treated with insulin showed decreased glucose tolerance but no additional modifications in the lipoprotein profile or in the composition of aortic tissue. Therefore, insulin initially prevents alterations in LDL, induced by the semi-synthetic diet, prevention which is not maintained in the long term.

Animals↗
PubMed1983

Relationship between metabolism and composition of low density lipoproteins in rabbits on semi-purified diet.

The metabolism of 125I-labelled apoprotein of low density lipoproteins was studied in rabbits fed either commercial or semi-purified, cholesterol-free, diet. The rise in apo-LDL intravascular pool size observed in the semi-purified group is accompanied by a marked decrease in the fractional catabolic rate and an increase in the total catabolic rate. The semi-purified diet induces an increase in the cholesterol ester/triglyceride ratio of the LDL which is normalized by cholestyramine therapy. The concomitant alterations in both LDL metabolism and lipid composition raise the possibility that enrichment of LDL in cholesterol esters is a consequence of the delayed LDL clearance from the plasma.

Animals↗
PubMed1980

Breed differences in nutritionally induced hyperlipoproteinemia in the rabbit.

The influence of a high-fat, cholesterol-free diet on the lipoprotein pattern is compared in New Zealand hyperresponder and Fauve de Bourgogne hyporesponder rabbits. Quantitative as well as qualitative differences were observed. The high-fat diet induces an increase in both LDL and HDL in the Fauve de Bourgogne, the ratio VLDL + LDL/HDL cholesterol being unchanged. By contrast, New Zealand rabbits present a greater increase in plasma cholesterol which is mainly transported by the VLDL and the LDL. Consequently the proportion of HDL cholesterol is markedly decreased. The breed difference in response to the diet is also noted in lipoproteins composition since only New Zealand rabbits show abnormal VLDL. These results are discussed in terms of differences in susceptibility to experimental atherosclerosis reported between the two strains.

Animals↗
PubMed1980

Lipoprotein modifications with changing dietary proteins in rabbits on a high fat diet.

Rabbits received a high-fat diet containing either casein or soya protein. Casein, in contrast to soya, enhanced the effect of the high-fat diet on the rise in plasma and liver cholesterol. The very low density lipoprotein (VLDL) and low density lipoprotein (LDL) of animals receiving casein showed an enrichment in cholesterol esters which coincided with a decrease in the triglyceride content. These cholesterol-rich beta lipoproteins may contribute to the potential atherogenicity of casein.

Animals↗