The Effect of Low Molecular Weight Dextran Infusions on Plasma Lipids and Lipoproteins

1970 ◽  
Vol 38 (2) ◽  
pp. 233-244 ◽  
Author(s):  
T. P. Whitehead ◽  
P. W. Dykes ◽  
J. Gloster ◽  
P. Harris

1. Infusions of Dextran 40 induced a pronounced fall in the plasma concentration of cholesterol, in the absence of marked changes in plasma volume. Similar falls occurred in the plasma concentrations of phospholipids, triglyceride and low density lipoprotein. It was further observed that the return to normal was slow, and at 15 days was still incomplete. 2. Lipoprotein turnover studies failed to demonstrate altered rates of catabolism or evidence for altered synthetic rates. They were better interpreted in terms of redistribution from the plasma to the rest of the extracellular fluid, although there was no indication as to its exact site.

1977 ◽  
Vol 6 (4) ◽  
pp. 348-358
Author(s):  
Mary L. Ellins ◽  
James B. Campbell

By using trypsin-treated human type O cells as indicators, we compared the abilities of four polyanion-divalent cation combinations (heparin-MnCl 2 ; high-and low-molecular-weight dextran sulfate-CaCl 2 ; and sodium polyanetholesulfonate [SPS]-CaCl 2 ) for removal of serum non-immunoglobulin (lipoprotein) inhibitors of rubella hemagglutination. The combination of SPS-CaCl 2 was found to be the most effective, precipitating completely the pre-β and β-lipoproteins and reducing the α-lipoprotein levels by more than 50%. Hemagglutination patterns after this treatment were clear and stable, and, when normal sera were tested, hemagglutination-inhibition (HI) titers were comparable to those obtained after standard heparin-MnCl 2 treatment. High-molecular-weight dextran sulfate-CaCl 2 removed serum lipoproteins almost as effectively as SPS-CaCl 2 . However, problems of nonspecific agglutination and the heavy hemagglutination patterns resulting made this combination unacceptable for routine purposes. Neither low-molecular-weight dextran sulfate-CaCl 2 nor heparin-MnCl 2 removed the pre-β lipoproteins completely, and occasionally traces of β-lipoprotein also remained after treatment. The presence of pre-β lipoproteins in normal sera after treatment may be of no consequence in the HI test since we have found that the very-low-density lipoprotein fractions obtained by ultracentrifugal methods from normal sera (those corresponding to the pre-β fractions obtained by electrophoresis) had no HI activity. However, very-low-density lipoprotein fractions from all hyperlipemic sera tested had HI activity (titers ranging from 1:16 to 1:1,024) which, in the majority of cases, was not eliminated after heparin-MnCl 2 treatment. In every case, treatment with SPS-CaCl 2 removed this nonspecific activity completely. Since hyperlipemic sera may occasionally be encountered in routine rubella HI antibody testing, we recommend the use of SPS-CaCl 2 rather than heparin-MnCl 2 for pretreatment of sera.


1976 ◽  
Vol 29 (4) ◽  
pp. 317 ◽  
Author(s):  
RW Burley ◽  
WA Davies

Further studies have been made of the physical properties of hen's apovitellenin I, the principal low-molecular-weight protein from the high-lipid low density lipoprotein of the yolk of hen's eggs. The methods used included chromatography, sedimentation, viscosity, optical rotation, and spin labelling; the solvents used were aqueous urea, and, for some experiments, aqueous formamide. It is concluded that at neutral pH the protein is present in these solvents as an aggregate of molecular weight 36000 corresponding to a tetramer. Below about pH 4�5 solutions of the tetramer increased greatly in viscosity; furthermore, a covalently bound spin label increased in mobility. These changes were reversible and were apparently the result of dissociation of the tetramer to a dimer. This dissociation did not involve a change in the proportion of a-helix. In contrast to the results of previous experiments, it now seems probable that the apovitellenin I dimer is stabilized by an interchain disulphide bond.


1973 ◽  
Vol 45 (5) ◽  
pp. 583-592 ◽  
Author(s):  
Gilbert R. Thompson ◽  
J. Paul Miller

1. Plasma lipids and lipoproteins have been studied in control subjects and patients with various types of steatorrhoea. 2. Low plasma cholesterol levels were found in malabsorbers and were associated with decreased amounts of low-density lipoprotein (LDL) in males and high-density lipoprotein (HDL) in females. 3. Serum triglyceride levels were normal in males, but exceeded control values in some of the females, due to an increase in very-low-density lipoprotein. 4. LDL composition was abnormal in both male and female malabsorbers, with a decreased proportion of cholesterol ester and an increased proportion of triglyceride. There was also an increased proportion of triglyceride in HDL. 5. These findings show that malabsorption markedly influences not only the concentration but also the composition of plasma lipoproteins.


2006 ◽  
Vol 27 (13) ◽  
pp. 2575-2581 ◽  
Author(s):  
Angelo Zinellu ◽  
Salvatore Sotgia ◽  
Elisabetta Zinellu ◽  
Marilena Formato ◽  
Salvatorica Manca ◽  
...  

1984 ◽  
Vol 51 (02) ◽  
pp. 186-188 ◽  
Author(s):  
A Szczeklik ◽  
R J Gryglewski ◽  
K Sladek ◽  
E Kostka-Trąbka ◽  
A Żmuda

SummaryDihomo-γ-linolenic acid (DHLA), a precursor of monoenoic anti-aggregatory prostaglandins (PGE1, PGD2), was administered for 4 weeks in a daily dose of 1.0 g into 33 patients with atherosclerosis on a basis of a double-blind trial. Comparison of treatment and placebo groups revealed elevation of DHLA in red cell lipids in DHLA-treated subjects. No differences, however, between the two groups could be observed in platelet aggregability, thromboxane A2 generation by platelets, serum cholesterol, PGE1 and PGE2 levels, and in inhibitory activity of low-density lipoproteins against prostacyclin synthetizing system in arteries. The dietary supplementation used did not lead to distinct antithrombotic effects.


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