Redistribution of cholesterol and β-sitosterol between Intralipid and rat plasma lipoproteins and red blood cells in vivo

1988 ◽  
Vol 66 (12) ◽  
pp. 1312-1321 ◽  
Author(s):  
G. Kakis ◽  
A. Kuksis ◽  
W. C. Breckenridge
Keyword(s):  
Rat Plasma ◽  
Scintillation Counting ◽  
Plasma Lipoproteins ◽  
High Density Lipoproteins ◽  
Gas Liquid Chromatography ◽  
Male Wistar Rats ◽  
Red Blood Cell Membranes ◽  
Vldl Fraction ◽  
Layer Chromatography

Male Wistar rats were injected intravenously with 2 mL of Intralipid containing 7.5 × 105 counts per minute (cpm) [14C]cholesterol and 7.5 × 105 cpm β-[3H]sitosterol. Blood was withdrawn immediately and at 5, 10, 20, 60,120, and 1440 min after injection from different animals. Plasma and red cells were separated and washed by conventional centrifugation, while lipoprotein density classes corresponding to chylomicrons, very low (VLDL), low (LDL), and high density lipoproteins (HDL) were isolated by ultracentrifugation. Total lipid and sterol compositions were determined by thin-layer chromatography in combination with gas–liquid chromatography, whereas radioactivity was measured by scintillation counting. The ratio of [14C]cholesterol/β-[3H]sitosterol rose from 1 to 3.65 in the plasma VLDL fraction, whereas that in the LDL and HDL fractions were equilibrated at about 2, following an initial transient increase in favour of cholesterol. The appearance and disappearance of the radioactivity from LDL and HDL fractions exhibited precursor–product relationship owing probably to the conversion of the Intralipid into an intermediate lipoprotein-X-like particle, which possesses a density similar to that of LDL. The radioactive cholesterol and β-sitosterol were incorporated into the red blood cell membranes at nearly similar initial rates, while at later times the incorporation of cholesterol was much preferred.

Origin and Fate of Cholesterol in Rat Plasma Lipoproteins in vivo

1985 ◽  
Vol 29 (3) ◽  
pp. 160-174 ◽  
Author(s):  
T. Magot ◽  
G. Champarnaud ◽  
R. Anfreville ◽  
C. Lutton ◽  
F. Chevallier
Keyword(s):  
Rat Plasma ◽  
Plasma Lipoproteins

scholarly journals Hepatic endothelial lipase antiserum influences rat plasma low and high density lipoproteins in vivo

FEBS Letters ◽  
1979 ◽  
Vol 104 (2) ◽  
pp. 384-388 ◽  
Author(s):  
Timo Kuusi ◽  
Paavo K.J. Kinnunen ◽  
Esko A. Nikkilä
Keyword(s):  
Rat Plasma ◽  
High Density ◽  
High Density Lipoproteins ◽  
Endothelial Lipase

Oxidative stress as a mechanism of combined OTA and CTN toxicity in rat plasma, liver and kidney

2018 ◽  
Vol 38 (4) ◽  
pp. 434-445 ◽  
Author(s):  
D Rašić ◽  
V Micek ◽  
MS Klarić ◽  
M Peraica
Keyword(s):  
Oxidative Stress ◽  
Rat Plasma ◽  
Protein Carbonyl ◽  
Protein Carbonyls ◽  
Lower Plasma ◽  
Sod Activity ◽  
Male Wistar Rats ◽  
Liver And Kidney ◽  
Gpx Activity

Ochratoxin A (OTA) and citrinin (CTN) commonly coexist in grains. Aiming to evaluate oxidative stress in OTA + CTN toxicity, male Wistar rats were orally treated with two doses of OTA (0.125 and 0.250 mg kg−1 of body weight (b.w.)), CTN (2 mg kg−1 of b.w.) and resveratrol (RSV; 20 mg kg−1 of b.w.) and combined daily during 3 weeks. Protein carbonyl concentrations were measured in kidneys and liver; catalytic activity of glutathione peroxidase (GPx), superoxide dismutase (SOD), catalase (CAT) and glutathione (GSH) level in plasma, kidneys and liver, while malondialdehyde (MDA) concentration was measured in plasma, kidneys, liver and urine. Mycotoxin treatment significantly increased MDA concentration in plasma and kidney and decreased SOD activity in the liver. Rats treated with CTN and OTA125 + CTN had lower plasma GPx activity. Concentration of GSH in the kidney and protein carbonyls in the kidney and liver as well as GPx activity in the kidney and liver, SOD activity in the kidney and CAT activity in the liver were not affected. Protective effect of RSV was observed on GSH in the kidney and plasma and MDA in the kidney, plasma and urine. Oxidative stress is involved in OTA + CTN toxicity in vivo because such treatment affects parameters of oxidative stress, particularly in plasma. RSV can reduce but not overcome oxidative stress induced by combined OTA and CTN treatment.

scholarly journals Species Differences in the Proportion of Plasma Lipoprotein Lipid Carried by High-Density Lipoproteins Influence the Distribution of Free and Liposomal Nystatin in Human, Dog, and Rat Plasma

1999 ◽  
Vol 43 (6) ◽  
pp. 1424-1428 ◽  
Author(s):  
Manisha Ramaswamy ◽  
Thomas L. Wallace ◽  
Paul A. Cossum ◽  
Kishor M. Wasan
Keyword(s):  
Low Density Lipoprotein ◽  
Density Lipoprotein ◽  
Rat Plasma ◽  
High Density ◽  
Plasma Lipoprotein ◽  
Lipoprotein Cholesterol ◽  
Plasma Lipoproteins ◽  
High Density Lipoproteins ◽  
Lipoprotein Lipid ◽  
Triglyceride Rich Lipoprotein

ABSTRACT The objective of this study was an interspecies comparison of free nystatin (NYS) and liposomal NYS (Nyotran) distribution in plasma. NYS and liposomal NYS at concentrations of 5, 10, and 20 μg of NYS/ml were incubated in human, dog, and rat plasma for 5, 60, and 180 min at 37°C. Following these incubations, plasma samples were separated into their high-density lipoprotein (HDL), triglyceride-rich lipoprotein, low-density lipoprotein, and lipoprotein-deficient plasma (LPDP) fractions by density-gradient ultracentrifugation, and each fraction was assayed for NYS by high-pressure liquid chromatography. Total plasma and lipoprotein cholesterol, triglyceride, and protein concentrations in each human, dog, or rat plasma sample were determined by enzymatic assays. When NYS and liposomal NYS were incubated in human, dog, or rat plasma, the majority of the NYS was recovered in the LPDP fraction. For the 5- and 60-min incubation times for all plasmas measured, a significantly greater percentage of NYS was recovered in the lipoprotein fraction (primarily HDL) following the incubation of liposomal NYS than following the incubation of NYS. There was a significant correlation between the lipoprotein lipid and protein profiles in human, dog, and rat plasmas and the distribution of NYS and liposomal NYS in plasma. In particular, differences in the proportion of plasma lipoprotein cholesterol, triglyceride, and apolar lipids (cholesteryl ester and triglycerides) carried by HDL influenced the distribution of NYS and liposomal NYS within plasmas of different species. These findings suggest that the distribution of NYS among plasma lipoproteins of different species is defined by the proportion of lipid carried by HDL, and this is possibly an important consideration when evaluating the pharmacokinetics, toxicities, and activities of these compounds following administration to different animal species.

Replacement of endogenous phospholipids in rat plasma lipoproteins during intravenous infusion of an artificial lipid emulsion

1978 ◽  
Vol 56 (6) ◽  
pp. 630-639 ◽  
Author(s):  
A. Kuksis ◽  
W. C. Breckenridge ◽  
J. J. Myher ◽  
G. Kakis
Keyword(s):  
Intravenous Infusion ◽  
Egg Yolk ◽  
Rat Plasma ◽  
Plasma Lipoproteins ◽  
Complete Analysis ◽  
Cholesteryl Esters ◽  
Apparent Clearance ◽  
Male Wistar Rats ◽  
Gradual Accumulation ◽  
Apoprotein Composition

Male Wistar rats, weighing 250–300 g, were intravenously infused (0.33 ml/h per 100 g body weight) with an artificial emulsion of soybean triacylglycerols and egg yolk phospholipids (Intralipid) for various periods of time ranging from a few hours to a few days. About 0.5 h after the infusion, the animals were sacrificed, various classes of plasma lipoproteins were isolated by centrifugation, and the total lipid profiles of the fractions were determined by high temperature gas chromatography. The lipoproteins collected after 24 h of infusion were subjected to a complete analysis of the molecular species of the various lipid classes. It was shown that continuous intravenous infusion of Intralipid, despite rapid apparent clearance of the visible lipid particles, resulted in a gradual accumulation of exogenous phosphatidylcholine and sphingomyelin, free cholesterol, and plant sterols in the plasma, which displaced the endogenous phospholipids and sterols from the various lipoproteins. At 24 h, about 70% of the endogenous phospholipid of all the plasma lipoproteins was replaced by egg yolk phospholipids of the Intralipid. Under the same conditions, no displacement nor exchange was observed of endogenous cholesteryl esters for exogenous triacylglycerols in any of the lipoprotein classes. Intralipid infusion for periods up to 3 days results in a limited further displacement of endogenous phospholipids by exogenous lipids in the plasma lipoproteins, but a complete substitution was not achieved because of a continued secretion of lipoproteins containing endogenous phospholipids. The infusion of Intralipid led to a significant increase in the proportion of the phospholipid and free sterol in all lipoproteins, which decreased the calculated diameter of the particles by about one-half. Only minor changes were seen in the lipid to protein ratios of the lipoproteins and in their apoprotein composition.

Hepatic and intestinal contribution of two forms of apolipoprotein B to plasma lipoprotein fractions in the rat

1981 ◽  
Vol 59 (8) ◽  
pp. 693-699 ◽  
Author(s):  
Charles E. Sparks ◽  
Oleh Hnatiuk ◽  
Julian B. Marsh
Keyword(s):  
Amino Acids ◽  
Apolipoprotein B ◽  
Corn Oil ◽  
Gel Filtration ◽  
Molecular Size ◽  
Plasma Lipoproteins ◽  
High Density Lipoproteins ◽  
Apo B ◽  
Triglyceride Rich Lipoprotein

The in vivo incorporation of labeled amino acids into two forms of apolipoprotein B of nascent hepatic, nascent intestinal, and plasma lipoproteins was studied. Using SDS–gel filtration column chromatography rat apolipoprotein B was separated into two proteins of higher (apo Bh) and of lower (apo B1) molecular size and the incorporation of label into each was measured. When livers isolated from fed rats were perfused with 3H-labeled amino acids, radioactivity was incorporated into both forms of apo B of the d < 1.060 fractions (very low (VLDL), intermediate (IDL), and low (LDL) density lipoproteins) with a labeling ratio of apo B1 to apo Bh of 0.8. When mesenteric lymph was collected from corn oil fed rats intraduodenally injected with 3H-labeled amino acids, radioactivity was mainly incorporated into apo B1 of chylomicrons and VLDL with apo B1 to apo Bh, labeling ratios of 14 and 44, respectively. Plasma was isolated 2 h after intraperitoneal injection of 3H-labeled amino acids into chow fed rats and lipoproteins were isolated by sequential density ultracentrifugation. The labeling ratio of apo B1 and apo Bh decreased from 4.2 in VLDL to 0.5 in LDL indicating a progressive enrichment of apo Bh in the LDL fraction. High density lipoproteins (HDL) contained less than 4% of the total labeled apo B and was enriched in apo B1. The results of this study indicate that the liver synthesizes both forms of apo B while the intestine synthesizes almost entirely apo B1. Since both apo B proteins are secreted primarily by the liver into VLDL, the results are consistent with preferential removal of apo B1 during triglyceride-rich lipoprotein catabolism and entry of hepatically derived apo Bh into LDL.

Biosynthesis of diacylglycerols by rat intestinal mucosa in vivo

1976 ◽  
Vol 54 (2) ◽  
pp. 137-144 ◽  
Author(s):  
W. C. Breckenridge ◽  
S. K. F. Yeung ◽  
A. Kuksis ◽  
J. J. Myher ◽  
M. Chan
Keyword(s):  
Fatty Acids ◽  
Intestinal Mucosa ◽  
Weight Fraction ◽  
Gas Liquid Chromatography ◽  
Long Chain Fatty Acids ◽  
Butter Oil ◽  
Arachidonic Acids ◽  
Layer Chromatography

The biosynthesis of diacylglycerols was studied in rat intestinal mucosa during in vivo absorption of a low molecular weight fraction of butter oil and of the corresponding medium and long chain fatty acids. The experimental fat solutions were given by stomach tube to the animals after a 24-h fast and mucosal scrapings were collected 3 h later. The lipids were isolated and the acylglycerols determined by combined thin-layer chromatography gas–liquid chromatography techniques and stereospecific analyses. Free fatty acid feeding led mainly to, sn-1,2-diacylglycerols, which contained exogenous and endogenous fatty acids. During triacylglycerol feeding, both.sn-1,2- and sn-2,3-diacylglycerols were recovered in significant amounts from the intestinal mucosa. The composition of the sn-2,3-diacylglycerols corresponded to that with exogenous fatty acids but the sn-1,2-diacylglycerols clearly contained both exogenous and endogenous fatty acids. In all cases it was possible to isolate endogenous sn-1,2-diacylglycerols made up largely of species with linoleic and arachidonic acids in the 2 position and palmitic and stearic acids in the 1 position, which apparently were not converted to triacylglycerols. The in vivo reacylation of 2-monoacylglycerols via both sn-1,2- and sn-2,3-diacylglycerols is in agreement with similar findings in vitro with everted sacs of rat intestinal mucosa.

scholarly journals The effects of insulin deficiency on the plasma clearance and exchange of high-density-lipoprotein phosphatidylcholine in rats

1992 ◽  
Vol 281 (3) ◽  
pp. 851-857 ◽  
Author(s):  
I J Martins ◽  
T G Redgrave
Keyword(s):  
Plasma Clearance ◽  
Cholesterol Acyltransferase ◽  
Density Lipoprotein ◽  
Cholesteryl Oleate ◽  
High Density ◽  
Plasma Lipoproteins ◽  
High Density Lipoproteins ◽  
Phospholipid Transfer ◽  
Plasma High Density

Triolein/cholesteryl oleate/cholesterol/phosphatidylcholine emulsions designed to model the lipid composition of chylomicrons were injected intravenously into control and streptozotocin-treated insulin-deficient rats. As previously described for lymph chylomicrons, the emulsion triolein was hydrolysed and phosphatidylcholine was transferred to the plasma high-density lipoproteins (HDL). This mechanism was used to introduce a phospholipid label into HDL in vivo. The subsequent clearance of phospholipid radioactivity from the plasma of insulin-deficient rats was significantly slower than in controls (P less than 0.025). Plasma clearance was similarly slower in insulin-deficient rats after injection of HDL that was previously labelled with radioactive phospholipids. After injection, the phospholipid label redistributed rapidly between the large-particle fraction of plasma lipoproteins (very-low- and low-density lipoproteins), and the lighter and heavier fractions of HDL. Compared with control rats, in insulin-deficient rats less of the phospholipid label was distributed to the lighter HDL fraction and more to the heavier HDL fraction, and this difference was not due to changes in activity of lecithin: cholesterol acyltransferase or in the apparent activity of phospholipid transfer protein. In insulin-deficient rats the changes in HDL phospholipid clearance and exchange appeared to be secondary to the associated hypertriglyceridaemia and the related changes in distribution of phospholipids between classes of plasma lipoproteins.

scholarly journals High density lipoproteins of blood plasma as a transport form of actinomycin D

2019 ◽  
Vol 17 (6) ◽  
pp. 64-69
Author(s):  
L. M. Polyakov ◽  
R. A. Knyazev ◽  
A. V. Ryabchenko ◽  
N. V. Trifonova ◽  
M. V. Kotova
Keyword(s):  
Actinomycin D ◽  
Physicochemical Characteristics ◽  
The Body ◽  
Plasma Lipoproteins ◽  
In Vivo Studies ◽  
High Density Lipoproteins ◽  
Transport Form ◽  
Apolipoprotein A

Introduction.The development of new and highly effective antitumor therapy is one of the priorities of pharmacology. The paper presents one of the solutions to the problem related to the development of transport forms of antitumor drugs.The aimof the study was to study the ability of various fractions of plasma lipoproteins (VLDLP, LDL, HDL) to interact with actinomycin D and show the role of HDL as a transport form of actinomycin D in the body cells.Material and methods. The studies were conducted using unlabeled and tritium-labeled actinomycin D, preparative ultracentrifugation of the rat plasma lipoprotein fractions, chromatography, and in vivo experiments with intravenous administration of HDL complexes with labeled actinomycin D.Results.The important role of HDL in the formation of complexes with actinomycin D in comparison with LDL and LPA was shown. The basic physicochemical characteristics of the interaction of HDL and apolipoprotein A-I with actinomycin were obtained. The constants of the association were of the order of 105 M-1, and the number of binding sites for the drug was 26 for HDL and 12 for apolipoprotein A-I. In vivo studies on rats, the highest radioactivity after intravenous injection of HDL complexes with tritium-labelled actinomycin D was observed in the adrenal glands, then in the liver and kidneys. The uptake of tritium-labelled actinomycin D was twice lower in the lungs, adipose tissue, thymus and spleen. The low uptake of the label was observed in the myocardial tissue.Conclusion.The results obtained demonstrate the feasibility of using HDL as a transport form of actinomycin D in body cells.

Binding of thyroxine and 3,5,3'-triiodothyronine to trout plasma lipoproteins

1992 ◽  
Vol 262 (5) ◽  
pp. E712-E720 ◽  
Author(s):  
P. J. Babin
Keyword(s):  
Nutritional Status ◽  
Binding Sites ◽  
Density Lipoprotein ◽  
High Density ◽  
Plasma Lipoproteins ◽  
High Density Lipoproteins ◽  
Minor Role ◽  
Very Low Density Lipoproteins

The plasma vectors of thyroid hormones (TH) in trout have been characterized. Plasma components were separated by density gradient ultracentrifugation after first labeling binding sites with trace levels of radioactive hormones, both in vivo and in vitro. Lipoproteins play only a minor role in humans but are major carriers of thyroxine (T4) and 3,5,3'-triiodothyronine (T3) in trout plasma. More than 67% of T4 and 89% of T3 were bound to lipoproteins (density less than 1.210 g/ml), predominantly to high-density lipoproteins (HDL), regardless of the nutritional status of the animals. The percentage of hormone bound to very-low-density lipoproteins, on the other hand, was proportional to their concentration and thus to nutritional status. T3 and T4 could also bind to vitellogenin, a very-high-density lipoprotein, which could transfer TH to the yolk of oocytes. Homologous ligand displacement indicated that T3 could bind to at least two classes of saturable sites in the plasma. In addition, plasma HDL were the major binding sites with low affinity (1.7 +/- 0.4 x 10(5) M-1) but with high capacity (3.1 +/- 0.3 x 10(-5) M). In conclusion, these results show that lipoproteins are the principal binding sites of TH in trout plasma.

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