Studies on the plasma glycolipoprotein synthesis by the isolated perfused liver: effect of early choline deficiency

1969 ◽  
Vol 47 (2) ◽  
pp. 125-133 ◽  
Author(s):  
Sailen Mookerjea
Keyword(s):  
Trichloroacetic Acid ◽  
Liver Perfusion ◽  
Dietary Treatment ◽  
Plasma Lipoproteins ◽  
High Density Lipoproteins ◽  
Low Density ◽  
Choline Deficiency ◽  
Significant Impairment ◽  
Isolated Liver ◽  
Insoluble Protein Fraction

Isolated liver perfusion preparations have been used to study the incorporation of glucosamine-1-14C into plasma glycoproteins and glycolipoproteins. The livers obtained from 2-day-choline-deficient rats and perfused with blood obtained from rats on similar dietary treatment showed, compared to controls, an impairment of incorporation of radioactive glucosamine into the trichloroacetic-acid-insoluble protein fraction of plasma during the progress of perfusion. The rate of disappearance of radioactivity in the trichloroacetic-acid-soluble fraction of plasma during perfusion was not affected by choline deficiency. Synthesis of plasma glycolipoproteins as judged by the progressively increased incorporation of radioactivity showed a very significant impairment of synthesis of very low-density (d < 1.006) and low-density (d > 1.006–1.063) glycolipoproteins in early choline deficiency. A similar inhibition of synthesis of plasma proteins of d > 1.21 ("lipid acceptor protein") was observed, whereas the synthesis of high-density lipoproteins (d < 1.063–1.21) was not affected in choline deficiency.The fatty liver in choline deficiency appears to result from an impairment of plasma low-density glycolipoprotein synthesis. A postulation has been made on the stepwise biosynthesis of plasma lipoproteins on the basis of these and earlier studies.

scholarly journals IMMUNOCHEMICAL STUDIES ON HUMAN PLASMA LIPOPROTEINS

1957 ◽  
Vol 105 (1) ◽  
pp. 49-67 ◽  
Author(s):  
Frederick Aladjem ◽  
Miriam Lieberman ◽  
John W. Gofman
Keyword(s):  
Human Plasma ◽  
Plasma Protein ◽  
Protein Fraction ◽  
Low Density Lipoproteins ◽  
High Density ◽  
Plasma Lipoproteins ◽  
High Density Lipoproteins ◽  
Low Density ◽  
Plasma Protein Fraction ◽  
Free Plasma

Low density human plasma lipoproteins Sf 17+, Sf 13, and Sf 6, high density lipoproteins 2 and 3, and a lipoprotein-free plasma protein fraction were isolated from human plasma by ultracentrifugal methods. It was found that human plasma lipoproteins are immunochemically distinct from the non-lipoprotein containing plasma protein fraction. Lipoprotein fractions of a given hydrated density, isolated from different individuals, were found to be immunochemically indistinguishable by qualitative absorption tests. Qualitative antigenic differences were shown to exist between low density lipoproteins and high density lipoproteins. Quantitative precipitin reactions showed that low density lipoproteins Sf 6 and Sf 13 were immunochemically very similar. However, they differed with respect to the amount of antigen nitrogen required for maximum precipitation. Agar diffusion analyses were performed; the results suggest heterogeneity of lipoproteins by this criterion.

scholarly journals Characterization of plasma lipoproteins separated and purified by agarose-column chromatography

1974 ◽  
Vol 139 (1) ◽  
pp. 89-95 ◽  
Author(s):  
Lawrence L. Rudel ◽  
Jason A. Lee ◽  
Manford D. Morris ◽  
James M. Felts
Keyword(s):  
Human Plasma ◽  
Column Chromatography ◽  
Low Density Lipoproteins ◽  
High Density ◽  
Plasma Lipoproteins ◽  
High Density Lipoproteins ◽  
Low Density ◽  
Very Low Density Lipoproteins ◽  
Simple Method ◽  
Lipoprotein Class

1. A simple method for isolation of individual human plasma lipoprotein classes is presented. In this technique, lipoproteins are removed from plasma at d1.225 by ultracentrifugation, after which they are separated and purified by agarose-column chromatography. 2. Three major classes are obtained after agarose-column chromatography. Separation between classes is excellent; more than 95% of the lipoproteins eluted from the column are recovered in the form of a purified lipoprotein class. 3. Each lipoprotein class was characterized immunologically, chemically, electrophoretically and by electron microscopy. A comparison of the properties of the column-isolated lipoproteins was made with very-low-density lipoproteins, low-density lipoproteins, and high-density lipoproteins separated by sequential ultracentrifugation at densities of 1.006, 1.063 and 1.21 respectively. 4. By each criterion, peak-I lipoproteins from the agarose column are the same as very-low-density lipoproteins, peak-II lipoproteins are the same as low-density lipoproteins, and peak-III lipoproteins are the same as high-density lipoproteins. Thus the lipoprotein classes isolated by both methods are similar if not identical. 5. The agarose-column separation technique offers the advantage of a two- to three-fold saving in time. In addition, the column-elution pattern serves as a recording of the size distribution of lipoproteins in plasma. 6. The most complete characterization is reported for human plasma lipoproteins. The results with rhesus-monkey and rabbit lipoproteins were identical.

Reduction in VLDL, but not HDL, in plasma of rats deficient in choline

1990 ◽  
Vol 68 (2) ◽  
pp. 552-558 ◽  
Author(s):  
Zemin Yao ◽  
Dennis E. Vance
Keyword(s):  
Gel Electrophoresis ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
High Density ◽  
Plasma Lipoproteins ◽  
Male Rats ◽  
High Density Lipoproteins ◽  
Choline Deficiency ◽  
Deficient Diet ◽  
Apo B

We have analyzed plasma lipoprotein levels in young male rats fed a choline-deficient diet for 3 days. We confirmed previous studies that choline deficiency promotes 6.5-fold accumulation of triacylgycerol in the liver (23.9 ± 6.0 versus 3.69 ± 0.92 μmol/g liver) and reduction of triacylglycerol concentration in plasma by 60% (0.17 ± 0.04 versus 0.46 ± 0.10μmol/mL plasma). Agarose gel electrophoresis showed that the plasma very low density lipoprotein (VLDL) levels were reduced in choline-deficient rats, but the concentration of plasma high density lipoproteins (HDL) was not affected. Sodium dodecyl sulfate – polyacrylamide gel electrophoresis of fractionated plasma lipoproteins revealed that the concentrations of apolipoproteins (apo) BH, BL, and E in VLDL from choline-deficient rats were 37.1, 11.0, and 37.2% of normal levels, respectively. In contrast, the amount of apo A-I, the major one in HDL, was almost unchanged. Correspondingly, there were decreased lipid (mainly phosphatidylcholine and triacylglycerol) levels in VLDL from choline-deficient rats, but no change in the levels of phosphatidylcholine, cholesterol, and cholesterol ester in HDL. There were similar levels of apo B and E (components of VLDL) in homogenates of livers from normal and choline-deficient rats, as determined by immunoblotting. These results support the hypothesis that choline deficiency causes reduction of VLDL, but not HDL, levels in plasma as a consequence of impaired hepatic VLDL secretion.Key words: choline deficiency, very low and high density lipoproteins, apolipoproteins, rat plasma.

STUDIES ON THE RAPID ACCUMULATION OF TRIGLYCERIDE IN THE LIVER IN CHOLINE DEFICIENCY

1965 ◽  
Vol 43 (10) ◽  
pp. 1733-1744 ◽  
Author(s):  
Sailen Mookerjea
Keyword(s):  
Acute Phase ◽  
Early Phase ◽  
Liver Perfusion ◽  
State Level ◽  
Choline Deficiency ◽  
Deficient Diet ◽  
Rapid Accumulation ◽  
Triphasic Pattern ◽  
Isolated Liver ◽  
Intact Rats

Studies with isolated liver perfusion preparations showed that, during 5 to 21 days of choline deficiency (acute phase), the livers fail to release any triglyceride into the perfusate, whereas during 1 to 2 days (early phase) and during 28 to 60 days of choline deficiency (prolonged phase), they tend to release triglyceride into the perfusate at a nearly normal rate. The rate of deposition of hepatic triglyceride in intact rats fed a choline-deficient diet showed a progression complementary to this triphasic pattern of triglyceride release, i.e. an early phase of slow triglyceride deposition and an acute phase of rapid accumulation followed by the establishment of a higher steady-state level. In the perfusion experiments changes in phospholipid levels in the perfusate followed the same pattern as the triglyceride levels. Increased uptake of free fatty acids by the choline-deficient livers was most marked after 2 days.In vitro additions of choline and several choline derivatives to the 5-day choline-deficient liver perfusion system were unable to restore triglyceride release. Similar studies with blood obtained from choline-supplemented rats showed a very significant restoration of triglyceride release into the perfusate.

scholarly journals Consequences of Interaction of a Lipophilic Endotoxin Antagonist with Plasma Lipoproteins

2000 ◽  
Vol 44 (3) ◽  
pp. 504-510 ◽  
Author(s):  
Jeffrey R. Rose ◽  
Maureen A. Mullarkey ◽  
William J. Christ ◽  
Lynn D. Hawkins ◽  
Melvyn Lynn ◽  
...  
Keyword(s):  
Human Blood ◽  
Gradient Centrifugation ◽  
Low Density Lipoproteins ◽  
Drug Binding ◽  
Size Exclusion ◽  
Plasma Lipoproteins ◽  
Cholesterol Concentration ◽  
High Density Lipoproteins ◽  
Low Density ◽  
Plasma Fraction

ABSTRACT E5531, a novel synthetic lipid A analogue, antagonizes the toxic effects of lipopolysaccharide, making it a potential intravenously administered therapeutic agent for the treatment of sepsis. This report describes the distribution of E5531 in human blood and its activity when it is associated with different lipoprotein subclasses. After in vitro incubation of [14C]E5531 with blood, the great majority (>92%) of material was found in the plasma fraction. Analysis by size-exclusion and affinity chromatographies and density gradient centrifugation indicates that [14C]E5531 binds to lipoproteins, primarily high-density lipoproteins (HDLs), with distribution into low-density lipoproteins (LDLs) and very low density lipoproteins (VLDLs) being dependent on the plasma LDL or VLDL cholesterol concentration. Similar results were also seen in a limited study of [14C]E5531 administration to human volunteers. The potency of E5531 in freshly drawn human blood directly correlates to increasing LDL cholesterol levels. Finally, preincubation of E5531 with plasma or purified lipoproteins indicated that binding to HDL resulted in a time-dependent loss of drug activity. This loss in activity was not observed with drug binding to LDLs or to VLDLs or chylomicrons. Taken together, these results indicate that E5531 binds to plasma lipoproteins, making its long-term antagonistic potency dependent on the plasma lipoprotein composition.

scholarly journals Membrane receptors for very low density lipoprotein (VLDL) inhibitor of lymphocyte proliferation

Blood ◽  
1981 ◽  
Vol 57 (6) ◽  
pp. 1055-1064 ◽  
Author(s):  
PI Yi ◽  
G Beck ◽  
S Zucker
Keyword(s):  
Dna Synthesis ◽  
Lymphocyte Proliferation ◽  
Human Lymphocytes ◽  
Low Density Lipoproteins ◽  
Membrane Receptors ◽  
Plasma Lipoproteins ◽  
High Density Lipoproteins ◽  
Scatchard Analysis ◽  
Low Density ◽  
Very Low Density Lipoproteins

Abstract Physiologic concentrations of human plasma very low density lipoproteins inhibit the DNA synthesis of lymphocytes stimulated by allogeneic cells or lectins. In this report we have compared the effects of isolated lipoproteins [very low density lipoproteins (VLDL), low density lipoproteins (LDL), and high density lipoproteins (HDL)] and lipoprotein-depleted plasma (LDP) on DNA synthesis by phytohemagglutinin-stimulated human lymphocytes. The relative potency for the inhibition of lymphocyte proliferation was VLDL greater than LDL greater than HDL greater than LDP. Fifty percent inhibition of DNA synthesis was observed at a VLDL protein concentration of 1.5--2.0 microgram/ml. We have further demonstrated the presence of specific receptors for VLDL on human lymphocytes. Native VLDL was more effective than LDL in competing for 125I-VLDL binding sites. Subsequent to binding to lymphocytes, 125I-VLDL was internalized and degraded to acid- soluble products. Based on a Scatchard analysis of VLDL binding at 4 degrees C, the number of VLDL receptors per lymphocyte was estimated at 28,000 +/- 1300. Based on an estimated mean binding affinity for the VLDL receptor complex at half saturation of approximately 8.8 X 10(7) liter/mole, it is estimated that 91% of lymphocyte VLDL receptors are occupied at physiologic VLDL concentrations in blood. Although the immune regulatory role of plasma lipoproteins is uncertain, we suggest tha VLDL and LDL-In may maintain circulating blood lymphocytes in a nonproliferative state via their respective cell receptor mechanisms.

scholarly journals Plasma lipoprotein and apolipoprotein distribution as a function of density in the rainbow trout (Salmo gairdneri)

1987 ◽  
Vol 246 (2) ◽  
pp. 425-429 ◽  
Author(s):  
P J Babin
Keyword(s):  
Plasma Proteins ◽  
Density Gradient Centrifugation ◽  
Gradient Centrifugation ◽  
Low Density Lipoproteins ◽  
Plasma Lipoproteins ◽  
Single Type ◽  
Salmo Gairdneri ◽  
High Density Lipoproteins ◽  
Low Density ◽  
Intermediate Density

I have previously described [Babin (1987) J. Biol. Chem. 262, 4290-4296] the apolipoprotein composition of the major classes of trout plasma lipoproteins. The present work describes the use of an isopycnic density gradient centrifugation procedure and sequential flotation ultracentrifugation to show: (1) the presence of intermediate density lipoproteins (IDL) in the plasma, between 1.015 and 1.040 g/ml; (2) the existence of a single type of Mr 240,000 apoB-like in the low density lipoproteins (LDL, 1.040 less than p less than 1.085 g/ml); (3) the presence of apoA-I-like (Mr 25,000) in the densest LDL; (4) the adequacy of 1.085 g/ml as a cutoff between the LDL and high density lipoproteins (HDL); (5) the accumulation of Mr 55,000 and 76,000 apolipoproteins and apoA-like apolipoproteins in the 1.21 g/ml infranatant. The fractionation of trout lipoprotein spectrum thus furnishes the distribution of the different lipoprotein classes and leads to the description of the constituent apolipoproteins, which account for about 36% of circulating plasma proteins in this species.

scholarly journals Inhibition of lymphocyte proliferation stimulated by lectins and allogeneic cells by normal plasma lipoproteins.

1977 ◽  
Vol 146 (6) ◽  
pp. 1791-1803 ◽  
Author(s):  
J H Morse ◽  
L D Witte ◽  
D S Goodman
Keyword(s):  
Human Plasma ◽  
Rank Order ◽  
Human Lymphocytes ◽  
Low Density Lipoproteins ◽  
Plasma Lipoproteins ◽  
High Density Lipoproteins ◽  
Low Density ◽  
Very Low Density Lipoproteins ◽  
Normal Plasma

Lipoproteins, isolated by sequential flotation at densities 1.006, 1.019, 1.063, and 1.21, were examined for their ability to inhibit human lymphocytes stimulated by allogeneic cells and by lectins (phytohemagglutinin-P and concanavalin A). All the classes of normal plasma lipoproteins inhibited lymphoproliferation when peripheral blood lymphocytes were cultured in autologous, heterologous, or lipoprotein-deficient plasma (d greater than 1.21). The rank order of inhibitory potency was intermediate density lipoprotein (IDL) greater than very low density lipoproteins (VLDL) greater than low density lipoproteins (LDL) greater than high density lipoproteins (HDL), regardless of the mode of stimulation. The concentrations of IDL, VLDL, and LDL required for complete inhibition of stimulated lymphoproliferation were considerably below the levels of each of these lipoproteins normally found in human plasma. In addition, the concentration of HDL required for 50-90% inhibition was in the range of HDL levels normally found in human plasma. Moreover, at relatively higher concentrations, lipoproteins suppressed the incorporation of [3H]thymidine into DNA below the levels seen with reseting, unstimulated lymphocytes. The results suggest that circulating lymphocytes may normally be highly suppressed by the combined effects of all the endogenous lipoproteins and that the lipoproteins may play important roles in vivo in modulating lymphocyte functions and responses.

Diagnosis of Type III Hyperlipoproteinemia by Chromatography of Plasma Lipoproteins on Columns Containing Agarose

1975 ◽  
Vol 21 (13) ◽  
pp. 1887-1891 ◽  
Author(s):  
James Shepherd ◽  
Christopher J Packard ◽  
Frances J Dryburgh ◽  
Jane L H C Third
Keyword(s):  
Low Density Lipoproteins ◽  
Plasma Lipoproteins ◽  
High Density Lipoproteins ◽  
Low Density ◽  
Very Low Density Lipoproteins ◽  
Type Iii ◽  
Elution Pattern ◽  
Type Iii Hyperlipoproteinemia ◽  
Primary Type ◽  
Relative Deficiency

Abstract Agarose column chromatography has been used to separate plasma lipoproteins into very-low-density lipoproteins (VLDL), low-density lipoproteins (LDL) and high-density lipoproteins (HDL). Applied to the diagnosis of primary type III hyperlipoproteinemia, the procedure is capable of demonstrating three characteristic and specific changes from normality in the elution pattern of lipoproteins from patients with this condition. In the type III profile there is (a) incomplete separation of VLDL from putative LDL material, (b) early elution of the type III LDL with respect to a normal LDL marker, and (c) relative deficiency of type III LDL with elution characteristics of normal LDL. We advocate the use of this method in the diagnosis of type III hyperlipoproteinemia.

scholarly journals Membrane receptors for very low density lipoprotein (VLDL) inhibitor of lymphocyte proliferation

Blood ◽  
1981 ◽  
Vol 57 (6) ◽  
pp. 1055-1064
Author(s):  
PI Yi ◽  
G Beck ◽  
S Zucker
Keyword(s):  
Dna Synthesis ◽  
Lymphocyte Proliferation ◽  
Human Lymphocytes ◽  
Low Density Lipoproteins ◽  
Membrane Receptors ◽  
Plasma Lipoproteins ◽  
High Density Lipoproteins ◽  
Scatchard Analysis ◽  
Low Density ◽  
Very Low Density Lipoproteins

Physiologic concentrations of human plasma very low density lipoproteins inhibit the DNA synthesis of lymphocytes stimulated by allogeneic cells or lectins. In this report we have compared the effects of isolated lipoproteins [very low density lipoproteins (VLDL), low density lipoproteins (LDL), and high density lipoproteins (HDL)] and lipoprotein-depleted plasma (LDP) on DNA synthesis by phytohemagglutinin-stimulated human lymphocytes. The relative potency for the inhibition of lymphocyte proliferation was VLDL greater than LDL greater than HDL greater than LDP. Fifty percent inhibition of DNA synthesis was observed at a VLDL protein concentration of 1.5--2.0 microgram/ml. We have further demonstrated the presence of specific receptors for VLDL on human lymphocytes. Native VLDL was more effective than LDL in competing for 125I-VLDL binding sites. Subsequent to binding to lymphocytes, 125I-VLDL was internalized and degraded to acid- soluble products. Based on a Scatchard analysis of VLDL binding at 4 degrees C, the number of VLDL receptors per lymphocyte was estimated at 28,000 +/- 1300. Based on an estimated mean binding affinity for the VLDL receptor complex at half saturation of approximately 8.8 X 10(7) liter/mole, it is estimated that 91% of lymphocyte VLDL receptors are occupied at physiologic VLDL concentrations in blood. Although the immune regulatory role of plasma lipoproteins is uncertain, we suggest tha VLDL and LDL-In may maintain circulating blood lymphocytes in a nonproliferative state via their respective cell receptor mechanisms.

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