Human lymphocyte complement receptors. Stimulation of lymphocyte RNA synthesis by complement-coated human red cells

Abstract C3b was bound to human red cells when serum complement was activated by addition of antibodies directed against different red cell antigens, and the rate of cleavage to C3dg was determined by assay for loss of bound C3c antigens using radiolabeled monoclonal anti-C3c. When C3b was bound by antibodies to antigens on branched-chain glycoproteins, cleavage to C3dg occurred more rapidly than when C3b was bound by antibodies to antigens closer to the red cell lipid bilayer. The rate of cleavage to C3dg also correlated directly with the number of complement receptors (CR1) per red cell, reflecting their role as cofactors in the cleavage of iC3b by factor I. Thus, the life span of C3b/iC3b on human red cells, which may be important for determining the rate and mechanism of clearance of C3-coated red cells, appears to depend on the CR1 status of the red cells and the characteristics of the antigen sites around which complement is bound.

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Stimulation of the Na+,K+-cotransport system by arginine vasopressin in human red cells

Regulatory Peptides ◽

10.1016/0167-0115(85)90212-5 ◽

1985 ◽

Vol 10 ◽

pp. 23-25

Author(s):

Javier Diez ◽

Carmen Miqueo ◽

Arancha Arrazola ◽

Jose I. Varela

Keyword(s):

Arginine Vasopressin ◽

Red Cells ◽

Cotransport System ◽

Stimulation Of ◽

Human Red Cells

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Stimulation of K+ fluxes by diuretic drugs in human red cells

Biochemical Pharmacology ◽

10.1016/0006-2952(84)90567-7 ◽

1984 ◽

Vol 33 (13) ◽

pp. 2013-2020 ◽

Cited By ~ 53

Author(s):

Ricardo P. Garay ◽

Corinne Nazaret ◽

Javier Diez ◽

Annie Etienne ◽

René Bourgain ◽

...

Keyword(s):

Red Cells ◽

Diuretic Drugs ◽

Stimulation Of ◽

Human Red Cells

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Effect of antigen site and complement receptor status on the rate of cleavage of C3c antigen from red cell bound C3b

Blood ◽

10.1182/blood.v71.3.786.bloodjournal713786 ◽

1988 ◽

Vol 71 (3) ◽

pp. 786-790

Author(s):

MS Currie ◽

PK Rustagi ◽

R Wojcieszak ◽

L Ziolkowski ◽

GD Ross ◽

...

Keyword(s):

Life Span ◽

Red Cells ◽

Complement Receptor ◽

Red Cell ◽

Complement Receptors ◽

Serum Complement ◽

Factor I ◽

Antigen Site ◽

Branched Chain ◽

Human Red Cells

C3b was bound to human red cells when serum complement was activated by addition of antibodies directed against different red cell antigens, and the rate of cleavage to C3dg was determined by assay for loss of bound C3c antigens using radiolabeled monoclonal anti-C3c. When C3b was bound by antibodies to antigens on branched-chain glycoproteins, cleavage to C3dg occurred more rapidly than when C3b was bound by antibodies to antigens closer to the red cell lipid bilayer. The rate of cleavage to C3dg also correlated directly with the number of complement receptors (CR1) per red cell, reflecting their role as cofactors in the cleavage of iC3b by factor I. Thus, the life span of C3b/iC3b on human red cells, which may be important for determining the rate and mechanism of clearance of C3-coated red cells, appears to depend on the CR1 status of the red cells and the characteristics of the antigen sites around which complement is bound.

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Modes of operation and variable stoichiometry of the furosemide- sensitive Na and K fluxes in human red cells.

The Journal of General Physiology ◽

10.1085/jgp.87.1.113 ◽

1986 ◽

Vol 87 (1) ◽

pp. 113-142 ◽

Cited By ~ 64

Author(s):

M Canessa ◽

C Brugnara ◽

D Cusi ◽

D C Tosteson

Keyword(s):

Experimental Evidence ◽

Reaction Scheme ◽

Red Cells ◽

Stoichiometric Ratio ◽

Coupled Transport ◽

K Transport ◽

Variable Stoichiometry ◽

Stimulation Of ◽

Human Red Cells ◽

External K

We report in this paper different modes of Na and K transport in human red cells, which can be inhibited by furosemide in the presence of ouabain. Experimental evidence is provided for inward and outward coupled transport of Na and K, Ki/Ko and Nai/Nao exchange, and uncoupled Na or K efflux. The outward cotransport of Na and K was defined as the furosemide-sensitive (FS) component of Na and K effluxes into choline medium and as the Cl-dependent or cis-stimulated component of the ouabain-resistant (OR) Na and K effluxes. Inward cotransport of Na and K was defined by the stimulation by external Na (Nao) of the K influx and the stimulation by external K (Ko) of the Na influx in the presence of ouabain. Both effects were FS and Cl dependent. Experimental evidence for an FS Ki/Ko exchange pathway of the Na/K cotransport was provided by (a) the stimulation by external K of FS K influx and efflux, and (b) the stimulation by internal Na or K of FS K influx in the absence of external Na. Evidence for an FS Nai/Nao exchange pathway was provided by the stimulation of FS Na influx by internal Na from a K-free medium (130 mM NaCl). This pathway was four to six times smaller than the Ki/Ko exchange. In cells containing only Na or K, incubated in media containing only Na or K, respectively, there was FS efflux of the cation without simultaneous inward transport (FS uncoupled Na and K efflux). The stoichiometric ratio of FS outward cotransport of Na and K into choline medium varied with the ratio of Nai-to-Ki concentrations, and when Nai/Ki was close to 1, the ratio of FS outward Na to K flux was also 1. In choline media, FS Na efflux was inhibited by external K (noncompetitively), whereas FS k efflux was stimulated. The stimulation of FS K efflux was due to the stimulation by Ko of the Ki/Ko exchange pathway. Thus, the stoichiometry of FS Na and K effluxes also varied in the presence of external K. A minimal model for a reaction scheme of FS Na and K transport accounts for cis stimulation, trans inhibition, and trans stimulation, and for variable stoichiometry of the FS cation fluxes.

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

Thrombosis and Haemostasis ◽

10.1055/s-0038-1651281 ◽

1968 ◽

Vol 20 (03/04) ◽

pp. 384-396 ◽

Cited By ~ 1

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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Stimulation of RNA Synthesis in the Salivary Gland Cells of Sciara Coprophila by an Electromagnetic Signal used for Treatment of Skeletal Problems in Horses

Electromagnetic Biology and Medicine ◽

10.3109/15368378709027727 ◽

1987 ◽

Vol 6 (1) ◽

pp. 37-47

Author(s):

Reba Goodman ◽

Ann Henderson

Keyword(s):

Salivary Gland ◽

Rna Synthesis ◽

Electromagnetic Signal ◽

Gland Cells ◽

Salivary Gland Cells ◽

Stimulation Of

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Metabolic control of the K+ channel of human red cells

The Journal of Membrane Biology ◽

10.1007/bf01871668 ◽

1990 ◽

Vol 116 (1) ◽

pp. 19-29 ◽

Cited By ~ 6

Author(s):

Pedro J. Romero ◽

Carlos E. Ortíz ◽

Carmelo Melitto

Keyword(s):

Metabolic Control ◽

Red Cells ◽

K Channel ◽

Human Red Cells

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Biosynthesis of growth hormone in the rat anterior pituitary gland. Stimulation of biosynthesis in vitro by insulin

Biochemical Journal ◽

10.1042/bj1341103 ◽

1973 ◽

Vol 134 (4) ◽

pp. 1103-1113 ◽

Cited By ~ 1

Author(s):

A. Betteridge ◽

M. Wallis

Keyword(s):

Growth Hormone ◽

Anterior Pituitary ◽

Rna Synthesis ◽

Glucose Utilization ◽

Actinomycin D ◽

Hormone Synthesis ◽

Pituitary Glands ◽

Hormone Biosynthesis ◽

Stimulation Of

The effect of insulin on the incorporation of radioactive leucine into growth hormone was investigated by using rat anterior pituitary glands incubated in vitro. A 50% stimulation over control values was observed at insulin concentrations above 2μm (280munits/ml). The effect was specific for growth hormone biosynthesis, over the range 1–5μm-insulin (140–700munits/ml). Lower more physiological concentrations had no significant effect in this system. Above 10μm (1.4 units/ml) total protein synthesis was also increased. The stimulation of growth hormone synthesis could be partially blocked by the addition of actinomycin D, suggesting that RNA synthesis was involved. Insulin was found to stimulate the rate of glucose utilization in a similar way to growth hormone synthesis. 2-Deoxyglucose and phloridzin, which both prevented insulin from stimulating glucose utilization, also prevented the effect of insulin on growth hormone synthesis. If glucose was replaced by fructose in the medium, the effect of insulin on growth hormone synthesis was decreased. We conclude that the rate of utilization of glucose may be an important step in mediating the effect of insulin on growth hormone synthesis.

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