Observations on the in vitro Effects of Chylomicra, Low-Density Lipoproteins and Phospholipids on Human Plasma Euglobulin Lysis

1963 ◽  
Vol 09 (01) ◽  
pp. 164-174 ◽  
Author(s):  
Albert R Pappenhagen ◽  
J. L Koppel ◽  
John H Olwin
Keyword(s):  
Human Plasma ◽  
Phosphatidyl Ethanolamine ◽  
Phosphatidyl Inositol ◽  
Plasma Lipoproteins ◽  
Low Density ◽  
Inhibitory Effects ◽  
Soybean Phospholipids ◽  
In Vitro Effects ◽  
Complete Precipitation

SummaryData have been presented on the in vitro effects of human chylomicra, low-density human plasma lipoproteins, and partially purified preparations of various phospholipids on human plasma euglobulin lysis. Euglobulin lysis was found to be accelerated by preparations of mixed soybean phospholipids (aso-lectin), cephalin, phosphatidyl inositol, phophatidyl serine and phosphatidyl ethanolamine. In contrast, it was found to be inhibited by preparations of human chylomicra, low-density human plasma liproproteins and lecithin. Inhibition of euglobulin lysis produced by any of these three agents could be diminished or completely overcome by the simultaneous presence of suitable levels of any one of the accelerating agents. In all cases studied, both inhibitory and accelerating effects were observed to be concentration-dependent. Evidence has been obtained to suggest that in the case of the accelerating agents the observed increased rate of euglobulin lysis is not a direct effect on lysis itself, but rather is due to more complete precipitation of plasminogen in the presence of these substances. On the other hand, it appears that the inhibitory effects observed are not related to the extent of plasminogen precipitation, but are actually true inhibitions of euglobulin lysis. The possible clinical significance of some of these observations has been briefly discussed.

In Vitro Effects of Ethanol on Rabbit Platelet Aggregation, Secretion of Granule Contents, and Cyclic AMP Levels in the Presence of Prostacyclin

1989 ◽  
Vol 61 (02) ◽  
pp. 254-258 ◽  
Author(s):  
Margaret L Rand ◽  
Peter L Gross ◽  
Donna M Jakowec ◽  
Marian A Packham ◽  
J Fraser Mustard
Keyword(s):  
Cyclic Amp ◽  
Inhibitory Effect ◽  
Rabbit Platelet ◽  
Inhibitory Effects ◽  
Low Concentrations ◽  
Rabbit Platelets ◽  
High Concentrations ◽  
In Vitro Effects ◽  
Aggregation Of Platelets

SummaryEthanol, at physiologically tolerable concentrations, inhibits platelet responses to low concentrations of collagen or thrombin, but does not inhibit responses of washed rabbit platelets stimulated with high concentrations of ADP, collagen, or thrombin. However, when platelet responses to high concentrations of collagen or thrombin had been partially inhibited by prostacyclin (PGI2), ethanol had additional inhibitory effects on aggregation and secretion. These effects were also observed with aspirin- treated platelets stimulated with thrombin. Ethanol had no further inhibitory effect on aggregation of platelets stimulated with ADP, or the combination of ADP and epinephrine. Thus, the inhibitory effects of ethanol on platelet responses in the presence of PGI2 were very similar to its inhibitory effects in the absence of PGI2, when platelets were stimulated with lower concentrations of collagen or thrombin. Ethanol did not appear to exert its inhibitory effects by increasing cyclic AMP above basal levels and the additional inhibitory effects of ethanol in the presence of PGI2 did not appear to be brought about by further increases in platelet cyclic AMP levels.

Studies on the Thromboplastic Effect of Human Plasma Lipoproteins

1976 ◽  
Vol 35 (01) ◽  
pp. 178-185 ◽  
Author(s):  
Helena Sandberg ◽  
Lars-Olov Andersson
Keyword(s):  
High Density Lipoprotein ◽  
Human Plasma ◽  
Platelet Rich Plasma ◽  
Low Density Lipoprotein ◽  
Density Lipoprotein ◽  
Plasma Lipoproteins ◽  
Very Low Density Lipoprotein ◽  
Low Density ◽  
Free Plasma ◽  
Good Agreement

SummaryHuman plasma lipoprotein fractions were prepared by flotation in the ultracentrifuge. Addition of these fractions to platelet-rich, platelet-poor and platelet-free plasma affected the partial thromboplastin and Stypven clotting times to various degrees. Addition of high density lipoprotein (HDL) to platelet-poor and platelet-free plasma shortened both the partial thromboplastin and the Stypven time, whereas addition of low density lipoprotein and very low density lipoprotein (LDL + VLDL) fractions only shortened the Stypven time. The additions had little or no effect in platelet-rich plasma.Experiments involving the addition of anti-HDL antibodies to plasmas with different platelet contents and measuring of clotting times produced results that were in good agreement with those noted when lipoprotein was added. The relation between structure and the clot-promoting activity of various phospholipid components is discussed.

Nonenzymatic glycosylation of low density lipoproteins in vitro. Effects on cell-interactive properties

Diabetes ◽  
1981 ◽  
Vol 30 (10) ◽  
pp. 875-878 ◽  
Author(s):  
B. Gonen ◽  
J. Baenziger ◽  
G. Schonfeld ◽  
D. Jacobson ◽  
P. Farrar
Keyword(s):  
Low Density Lipoproteins ◽  
Low Density ◽  
Nonenzymatic Glycosylation ◽  
In Vitro Effects

In Vitro Effects of the Acylated StreptokinasePlasminogen Activator Complex BRL 33 575 Incubated with Normal Human Plasma

1984 ◽  
Vol 51 (03) ◽  
pp. 403-405 ◽  
Author(s):  
B Lämmle ◽  
G Noll ◽  
T H Tran ◽  
A Lohri ◽  
F Duckert
Keyword(s):  
Human Plasma ◽  
Clinical Studies ◽  
Systemic Effects ◽  
In Vitro Experiments ◽  
Normal Human Plasma ◽  
Normal Human ◽  
Repeated Doses ◽  
In Vitro Effects ◽  
Activator Complex

SummaryThrombolysis with acylated streptokinase-plasminogen complexes is aimed to achieve fibrinolysis without systemic fibrinogenolysis. The p-aminobenzoyl-streptokinase-(Lys)-plasminogen-complex (BRL 33 575) should be particularly useful due to its slow deacylation rate. Unexpectedly, repeated doses of 10 mg of BRL 33 575 (corresponding to 310'000 streptokinase equivalent units) induced systemic effects in patients though less than streptokinase alone. In vitro incubation of normal human plasma with BRL 33 575 at concentrations used in patients resulted in nearly complete consumption of α2-antiplasmin and plasminogen and significant fibrinogenolysis within 3 hr. This demonstrates that - despite of slow deacylation of BRL 33 575 - the small amounts of activator generated are highly efficacious in activating plasma plasminogen under conditions in which no physiological clearance of the free activator takes place. Simulating the calculated activator release from BRL 33 575 by infusing equivalent amounts of streptokinase into plasma resulted in less pronounced effects. This is probably explained by anti-streptokinase antibodies which will neutralize the initially infused streptokinase but will be bound by BRL 33 575.Our in vitro experiments indicate that further clinical studies should be done with lower doses of BRL 33 575 or prolonged dosage intervals.

In Vitro Effects of Estrogens on the Δ4-Reduction of Testosterone by Rat Prostate and Liver Preparations

1973 ◽  
Vol 51 (6) ◽  
pp. 735-740 ◽  
Author(s):  
D. K. H. Lee ◽  
J. C. Young ◽  
Y. Tamura ◽  
D. C. Patterson ◽  
C. E. Bird ◽  
...  
Keyword(s):  
Phenolic Hydroxyl ◽  
Hydroxyl Group ◽  
Inhibitory Effects ◽  
Steroid Nucleus ◽  
In Vitro Effects ◽  
Rat Prostate ◽  
Steroid Structure ◽  
Soluble Fractions

The inhibitory effects of six estrogens (estradiol, estriol, ethynylestradiol, mestranol, diethylstilbestrol, and chlorotrianisene) on testosterone Δ4-reduction were studied in rat prostate and liver preparations. In the prostate homogenates only those estrogens with a complete steroid structure and a free phenolic hydroxyl group at position 3 of the steroid nucleus inhibited testosterone 5α-reduction when present at 600 times the concentration of testosterone. The inhibition by estradiol was found to be competitive for prostate homogenate, microsomal, and nuclear preparations. In the liver preparations (homogenate, microsomal, and soluble fractions) all six estrogens inhibited significantly when present at the same concentration as testosterone; diethylstilbestrol and ethynylestradiol were the most effective ones.

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 Fluorescence studies of protein–sterol relationships in human plasma lipoproteins

1974 ◽  
Vol 137 (2) ◽  
pp. 413-415 ◽  
Author(s):  
Rory J. M. Smith ◽  
Colin Green
Keyword(s):  
High Density Lipoprotein ◽  
Human Plasma ◽  
Low Density Lipoprotein ◽  
Density Lipoprotein ◽  
Tryptophan Fluorescence ◽  
High Density ◽  
Plasma Lipoproteins ◽  
Low Density ◽  
Fluorescence Studies ◽  
Esterified Sterols

Cholesta-5,7,9(11)-trien-3β-ol and its oleate ester were incorporated into human low-density lipoprotein and reconstituted high-density lipoprotein. The unesterified sterol was more efficient than its ester in quenching tryptophan fluorescence, especially in low-density lipoprotein. The results, which indicate that in such lipoproteins unesterified sterols are more closely associated with peptide than are esterified sterols, are used to assess possible structures for the lipoproteins.

scholarly journals Association of the Endotoxin Antagonist E5564 with High-Density Lipoproteins In Vitro: Dependence on Low-Density and Triglyceride-Rich Lipoprotein Concentrations

2003 ◽  
Vol 47 (9) ◽  
pp. 2796-2803 ◽  
Author(s):  
Kishor M. Wasan ◽  
Olena Sivak ◽  
Richard A. Cote ◽  
Aaron I. MacInnes ◽  
Kathy D. Boulanger ◽  
...  
Keyword(s):  
Human Plasma ◽  
Human Subjects ◽  
Low Density Lipoprotein ◽  
Density Lipoprotein ◽  
High Density ◽  
High Density Lipoproteins ◽  
Low Density ◽  
Distribution Profile ◽  
Transfer Activity

ABSTRACT The objective of this study was to determine the distribution profile of the novel endotoxin antagonist E5564 in plasma obtained from fasted human subjects with various lipid concentrations. Radiolabeled E5564 at 1 μM was incubated in fasted plasma from seven human subjects with various total cholesterol (TC) and triglyceride (TG) concentrations for 0.5 to 6 h at 37°C. Following these incubations, plasma samples were separated into their lipoprotein and lipoprotein-deficient fractions by ultracentrifugation and were assayed for E5564 radioactivity. TC, TG, and protein concentrations in each fraction were determined by enzymatic assays. Lipoprotein surface charge within control and phosphatidylinositol-treated plasma and E5564’s influence on cholesteryl ester transfer protein (CETP) transfer activity were also determined. We observed that the majority of E5564 was recovered in the high-density lipoprotein (HDL) fraction. We further observed that incubation in plasma with increased levels of TG-rich lipoprotein (TRL) lipid (TC and TG) concentrations resulted in a significant increase in the percentage of E5564 recovered in the TRL fraction. In further experiments, E5564 was preincubated in human TRL. Then, these mixtures were incubated in hypolipidemic human plasma for 0.5 and 6 h at 37°C. Preincubation of E5564 in purified TRL prior to incubation in human plasma resulted in a significant decrease in the percentage of drug recovered in the HDL fraction and an increase in the percentage of drug recovered in the TRL and low-density lipoprotein fractions. These findings suggest that the majority of the drug binds to HDLs. Preincubation of E5564 in TRL prior to incubation in normolipidemic plasma significantly decreased the percentage of drug recovered in the HDL fraction. Modifications to the lipoprotein negative charge did not alter the E5564 concentration in the HDL fraction. In addition, E5564 does not influence CETP-mediated transfer activity. Information from these studies could be used to help identify the possible components of lipoproteins which influence the interaction of E5564 with specific lipoprotein particles.

METABOLISM OF EHRLICH ASCITES TUMOR IN VITRO: SUBCELLULAR DISTRIBUTION OF PHOSPHOLIPIDS NEWLY FORMED FROM14C-LABELED PRECURSORS

1966 ◽  
Vol 44 (11) ◽  
pp. 1461-1468 ◽  
Author(s):  
V. Donisch ◽  
R. J. Rossiter
Keyword(s):  
Microsomal Fraction ◽  
Phosphatidyl Ethanolamine ◽  
Lipid Fraction ◽  
Specific Radioactivity ◽  
Phosphatidyl Inositol ◽  
Phosphatidyl Serine ◽  
Ethanolamine Phosphatidyl ◽  
Ehrlich Ascites ◽  
Ethanolamine Plasmalogen

When Ehrlich ascites cells were incubated in a suitable medium containing choline-1,2-14C, ethanolamine-1,2-14C, L-serine-14C, or glycerol-1-14C, radioactivity was recovered from the lipid fraction. With choline-1,2-14C, radioactivity was incorporated into the three choline-containing phospholipids, lecithin, choline plasmalogen, and sphingomyelin. Radioactivity from ethanolamine-1,2-14C was incorporated into phosphatidyl ethanolamine, ethanolamine plasmalogen, choline plasmalogen, and lecithin. Radioactivity from L-serine-14C was incorporated into phosphatidyl serine, serine plasmalogen, and phosphatide acid, with lesser amounts into phosphatidyl ethanolamine, lecithin, ethanolamine plasmalogen, choline plasmalogen, and sphingomyelin. Radioactivity from glycerol-1-14C was incorporated into the glycerophosphatides, phosphatidic acid, lecithin, phosphatidyl ethanolamine, phosphatidyl serine, phosphatidyl inositol, and choline plasmalogen. Radioactivity from this precursor was also incorporated into sphingomyelin.In all instances, radioactivity was recovered from the phosphatides in the nuclear, mitochondrial, and microsomal fractions of the tumor. Usually, the specific radioactivity of the phosphatides in the microsomal fraction exceeded that in the other two subcellular fractions.

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