Action of phospholipase a on aggregation of red cells and platelets

1976 ◽  
Vol 82 (6) ◽  
pp. 1761-1763
Author(s):  
G. Ya. Levin ◽  
Yu. A. Sheremet'ev
Keyword(s):  
Red Cells ◽  
Phospholipase A

scholarly journals Ultracytochemical Observations on Intracytoplasmic Lipids by Enzymic Digestive Methods: Histochemical Trials

1983 ◽  
Vol 31 (1A_suppl) ◽  
pp. 150-153 ◽  
Author(s):  
Sotokichi Morii
Keyword(s):  
Outer Membrane ◽  
Light Microscope ◽  
Red Cells ◽  
Phospholipase A ◽  
Naja Naja ◽  
Vibratome Section ◽  
Fatty Livers

The penetration of Rbizopus arrhizus lipase into ethioine fatty livers was examined histochemically. A free-floating, 30 μm thick Vibratome section of the livers perfused with aldehydes was shown to be suitable for ultracytochemical analysis by the lipase digestive method. Accessibility of phospholipids in the outer membrane of erythrocytes to Naja naja phospholipase A2 was observed under a light microscope, and intact red cells were used for the ultracytochemical analysis by the phospholipase digestive method. Ultracytochemical pictures of cytoplasmic lipids in these materials subjected to the enzymatic digestive method are presented.

Intermembrane lipid transfer duringTrypanosoma cruzi-induced erythrocyte membrane destabilization

Parasitology ◽  
1994 ◽  
Vol 108 (3) ◽  
pp. 323-334 ◽  
Author(s):  
H. D. Luján ◽  
D. H. Bronia
Keyword(s):  
Fatty Acids ◽  
Free Fatty Acids ◽  
Erythrocyte Membrane ◽  
Red Cells ◽  
Phospholipase A ◽  
Erythrocyte Membranes ◽  
Lipid Transfer ◽  
Independent Manner ◽  
Membrane Destabilization

SUMMARYThe ability ofTrypanosoma cruzito induce erythrocyte membrane destabilizationin vitrowas studied. Epimastigote forms adhered to human erythrocytes and caused fusion or lysis of the red cells, depending on the conditions of the interaction. Red cells were fused in the presence of calcium, while haemolysis was induced in the absence of the cation. Dextran 60 C facilitated fusion but delayed lysis. Optimum pH and temperature for fusion were 7·4 and 37 °C, respectively. Lipid alterations were produced in the plasma membrane of the red cell during the interaction with the parasite. A Ca2+-independent increase of lysophospholipids and free fatty acids was common to both the lysis and fusion processes. A relative increase of 1, 2-diacylglycerides was unique to the fusion process and these changes were dependent on Ca2+. The transfer of free fatty acids and lysophospholipids fromT. cruzito erythrocyte membranes was demonstrated using parasites pre-labelled with radioactive phospholipids. Pre-treatment of parasites with exogenous phospholipase A2abolished the fusogenicity, while lysis was increased. Neither fusion nor haemolysis occurred when the parasites were pre-treated with fatty acid free albumin, phospholipase A2inhibitors or when these compounds were present in the medium during the parasite-erythrocyte interaction. Our results suggest thatT. cruziinduces erythrocyte membrane destabilizationin vitroby transfer of lipid material in a calcium independent manner and that this ion is necessary for other membrane alterations that lead to erythrocyte fusion.

Differential Outcomes for Long Term ex vivo Lung Perfusion in a Porcine Model - With or without Red Cells?

2015 ◽  
Vol 63 (S 01) ◽  
Author(s):  
W. Sommer ◽  
M. Avsar ◽  
J. Salman ◽  
C. Kühn ◽  
I. Tudorache ◽  
...  
Keyword(s):  
Porcine Model ◽  
Ex Vivo ◽  
Lung Perfusion ◽  
Red Cells ◽  
Ex Vivo Lung Perfusion ◽  
Differential Outcomes

Liquoid Induced Stasis and the Generalized Shwartzman Reaction

1979 ◽  
Vol 41 (04) ◽  
pp. 804-810 ◽  
Author(s):  
Knut Nordstoga
Keyword(s):  
Red Cells ◽  
Renal Lesions ◽  
Intravenous Injections ◽  
Shwartzman Reaction ◽  
Glomerular Capillaries

SummaryThe composition of the occlusive material within dilated glomerular capillaries, following intravenous injections of Liquoid in blue foxes, was studied electron microscopically; it was found that it mainly consisted of a debris in which disintegrated red cells constituted the major component. Damaged platelets and necrotic endothelial remnants were other components. These observations were interpreted as a result of glomerular stasis, and it was concluded that stasis in glomerular capillaries is a basic event in the development of the renal lesions accompanying the generalized Shwartzman reaction.

Receptor Mediated Binding of the Fibrinolytic Components, Plasminogen and Urokinase, to Peripheral Blood Cells

1987 ◽  
Vol 58 (03) ◽  
pp. 936-942 ◽  
Author(s):  
Lindsey A Miles ◽  
Edward F Plow
Keyword(s):  
T Cells ◽  
B Cell ◽  
Peripheral Blood ◽  
Binding Sites ◽  
Blood Cells ◽  
High Capacity ◽  
Red Cells ◽  
Peripheral Blood Cells ◽  
Cellular Functions ◽  
Fibrinolytic Proteins

SummaryGlu-plasminogen binds to platelets; the monocytoid line, U937, and the human fetal fibroblast line, GM1380 bind both plasminogen and its activator, urokinase. This study assesses the interaction of these fibrinolytic proteins with circulating human blood cells. Plasminogen bound minimally to red cells but bound saturably and reversibly to monocytes, granulocytes and lymphocytes with apparent Kd values of 0.9-1.4 μM. The interactions were of high capacity with 1.6 to 49 × 105 sites/cell and involved the lysine binding sites of plasminogen. Both T cells and non-rosetting lymphocytes and two B cell lines saturably bound plasminogen. Urokinase bound saturably to gianulocytes, monocytes, non-rosetting lymphocytes and a B cell line, but minimally to T cells, platelets and red cells. Therefore, plasminogen binding sites of high capacity, of similar affinities, and with common recognition specificities are expressed by many peripheral blood cells. Urokinase receptors are also widely distributed, but less so than plasminogen binding sites. The binding ol plasminogen and/ or urokinase to these cells may lead to generation of cell- associated proteolytic activity which contributes to a variety of cellular functions.

Antithrombin Activity of Intact Human Platelets

1975 ◽  
Vol 34 (01) ◽  
pp. 115-126 ◽  
Author(s):  
Kiyoake Watanabe ◽  
Francis C Chao ◽  
James L Tullis
Keyword(s):  
Antithrombin Iii ◽  
Human Platelets ◽  
Significant Loss ◽  
Red Cells ◽  
Antithrombin Activity ◽  
Α2 Macroglobulin ◽  
Rapid Reaction ◽  
Pre Treatment ◽  
Different Characteristics

SummaryAntithrombin activity has been identified in intact washed human platelets. An apparent activity was demonstrated at platelet concentrations above 0.31 × 109/ml, when platelet suspensions were incubated with 2.0 NIH units/ml of thrombin. Neither red cells nor white cells revealed antithrombin activity. No significant loss of the platelet antithrombin activity was observed after ten successive washings or after treatment of platelets with antibodies to antithrombin III or α2-macroglobulin. Almost the same amount of antithrombin activity as normal platelets was demonstrated in the platelets from an afibrinogenemic patient. Pre-treatment of platelets with trypsin, papain, and neuroaminidase reduced the activity significantly, whereas lipase was without effect. The platelet antithrombin reacted with thrombin in less than 3 seconds, and this rapid reaction of platelet antithrombin was different from that of plasma antithrombin III or fibrinogen. The thrombin-like clotting activity of ancrod was inhibited by fibrinogen but not platelets. Also, unlike plasma antithrombin III or fibrinogen, brief exposure to heat (56° C or 60° C) reduced considerable amounts of platelet antithrombin activity. These results suggest that platelets possess a specific antithrombin with different characteristics from other known antithrombins.

In Vitro Assay of Platelet Adhesiveness with Washed and Tanned Human Red Cells

1968 ◽  
Vol 20 (03/04) ◽  
pp. 384-396 ◽  
Author(s):  
G Zbinden ◽  
S Tomlin
Keyword(s):  
Platelet Adhesion ◽  
Sodium Citrate ◽  
Blood Platelets ◽  
In Vitro Assay ◽  
Red Cells ◽  
Platelet Adhesiveness ◽  
Vitro Assay ◽  
In Vitro System ◽  
Human Red Cells

SummaryAn in vitro system is described in which adhesion of blood platelets to washed and tannic acid-treated red cells was assayed quantitatively by microscopic observation. ADP, epinephrine and TAME produced a reversible increase in platelet adhesiveness which was antagonized by AMP. With Evans blue, polyanetholsulfonate, phthalanilide NSC 38280, thrombin and heparin at concentrations above 1-4 u/ml the increase was irreversible. The ADP-induced increase in adhesiveness was inhibited by sodium citrate, EDTA, AMP, ATP and N-ethylmaleimide. EDTA, AMP and the SH-blocker N-ethylmaleimide also reduced spontaneous platelet adhesion to red cells. No significant effects were observed with adenosine, phenprocoumon, 5-HT, phthalanilide NSC 57155, various estrogens, progestogens and fatty acids, acetylsalicylic acid and similarly acting agents, hydroxylamine, glucose and KCN. The method may be useful for the screening of thrombogenic and antithrombotic properties of drugs.

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