Passive permeability of human red blood cells to calcium

1986 ◽  
Vol 250 (1) ◽  
pp. C26-C31 ◽  
Author(s):  
M. K. McNamara ◽  
J. S. Wiley

Ca2+ influx was measured into human erythrocytes in which efflux was blocked by either introduction of an intracellular Ca2+ chelator, introduction of the Ca2+ chelator followed by ATP depletion, or depletion of the Ca2+ pump cofactors ATP and Mg2+. The Ca2+ influx under all three conditions was 14-20 mumol . 1 cells-1 . h-1, which is an order of magnitude higher than the influx previously reported for cells depleted of either ATP or Mg2+ separately. The difference between the two values was explained by the finding of substantial Ca2+ efflux from the Ca2+-loaded ATP-depleted cells, whereas this efflux was insignificant from cells loaded with quin 2 and then ATP depleted. Under these latter conditions Ca2+ influx estimates the unidirectional permeability to this cation. Studies using this technique showed that Ca2+ influx was the same in media of isotonic sodium, potassium, lithium, choline, or magnesium chlorides. Moreover the dependence of Ca2+ influx on external Ca2+ concentration was well described by the sum of saturable and nonsaturable (linear) components.

1952 ◽  
Vol 96 (1) ◽  
pp. 1-15 ◽  
Author(s):  
Erwin Neter ◽  
Lee F. Bertram ◽  
Dorothy A. Zak ◽  
Miriam R. Murdock ◽  
Carl E. Arbesman

A study on hemagglutination and hemolysis by Escherichia coli O111 and O55 (rabbit) antisera and on hemagglutination and hemolysis inhibition by E. coli O111 and O55 antigens revealed the following facts. 1. Red blood cells of man, dog, rabbit, guinea pig, sheep, rat, and chicken adsorb E. coli O111 and O55 antigens and thus become specifically agglutinable by the homologous E. coli antisera. 2. The adsorption of these E. coli antigens is a function of the concentration of the antigen, the time (from 5 minutes to 2 hours) of treatment of the red blood cells with the antigen, and the concentration of the red blood cells used. 3. Red blood cells of man and sheep adsorb simultaneously both antigens, as indicated by the fact that both antisera give agglutination of all red blood cells. Complete agglutination does not occur when a mixture of red blood cells treated separately with the two antigens is added to one or the other of the two antisera. 4. Treatment of red blood cells of man with one of the antigens does not block the adsorption of the second antigen. Human cells treated with either or both antigens are still agglutinated by the homologous blood group (A, B, and Rh)-specific antibodies. 5. In the presence of guinea pig complement, E. coli O111 and O55 antisera produce hemolysis of modified human red blood cells in titers of the same order of magnitude as those giving hemagglutination and bacterial agglutination. The same antisera produce hemolysis of sheep cells treated with the identical antigens in titers exceeding by far those giving agglutination of modified human or sheep red blood cells. 6. Both sediment and supernate of a boiled E. coli suspension are capable of modifying red blood cells for E. coli hemagglutination; in contrast, the supernate obtained from an unboiled suspension and then heated does not modify red blood cells for hemagglutination, although it contains the antigen which can specifically adsorb E. coli antibodies, as shown by means of the hemagglutination and hemolysis inhibition tests. 7. Both the unheated and the boiled suspensions of E. coli O111 and O55 inhibit hemagglutination and hemolysis specifically. 8. Rabbit red blood cells modified by either E. coli O111 or 055 antigens, upon intravenous injection into rabbits, engender specific E. coli antibodies. The significance of the results is discussed.


1985 ◽  
Vol 249 (1) ◽  
pp. C124-C128 ◽  
Author(s):  
P. K. Lauf ◽  
C. M. Perkins ◽  
N. C. Adragna

The effects of incubation in anisosmotic media and of metabolic depletion on ouabain-resistant (OR) Cl--dependent K+ influxes stimulated by N-ethylmaleimide (NEM) were studied in human red blood cells using Rb+ as K+ analogue. The NEM-stimulated but not the basal Rb+-Cl- influx measured in phosphate-buffered anisosmotic media was found to be cell volume dependent. When cellular ATP, [ATP]c, was lowered to less than 0.10 of its initial level by exposure to nonmetabolizable 2-deoxy-D-glucose, the NEM-stimulated but not the basal Cl--dependent Rb+ influxes were abolished. Metabolically depleted red blood cells subsequently repleted by incubation in glucose plus inosine regained the NEM-inducible Rb+ (K+) transport activity. The difference in the time course of ATP breakdown and Rb+ influx inhibition suggests that energization of the NEM-stimulated Rb+ flux by metabolism may involve factors additional to ATP.


1984 ◽  
Vol 247 (3) ◽  
pp. C143-C149 ◽  
Author(s):  
G. A. Plishker

Cadmium and zinc increased the accumulation of calcium in human red blood cells by increasing passive influx without enhancing the permeability to other ions. The effect of cadmium and zinc appeared specific to these metals, because barium, magnesium, cobalt, strontium, manganese, and nickel had no effect. Changes in calcium uptake by extracellular sodium, potassium, and pH were not altered by zinc and cadmium. Inhibition of calcium uptake by quinine, oligomycin, and iodoacetate was not affected by cadmium or zinc. These results suggest that cadmium and zinc increase calcium movement through normal influx pathways. Cadmium and zinc acted synergistically apparently by different mechanisms. Zinc and cadmium differentially affected calcium uptake in different extracellular calcium concentrations. The cadmium effect was increased by low concentrations of 2-mercaptoethanol and above pH 8.0, while the zinc effect was less sensitive to these factors. These findings suggest that the cadmium effect involves a disulfide bond between cysteinyl residues and the zinc effect involves a different site.


Blood ◽  
2013 ◽  
Vol 121 (8) ◽  
pp. 1459-1468 ◽  
Author(s):  
Lola Svensson ◽  
Annika K. Hult ◽  
Robert Stamps ◽  
Jonas Ångström ◽  
Susann Teneberg ◽  
...  

Key Points A new histo-blood group system was discovered, based on the identification of Forssman glycolipid antigen on human red blood cells. A newly described polymorphism in the GBGT1 gene activates the encoded enzyme to synthesize Forssman antigen.


Blood ◽  
1983 ◽  
Vol 62 (1) ◽  
pp. 214-217 ◽  
Author(s):  
PA Aarts ◽  
PA Bolhuis ◽  
KS Sakariassen ◽  
RM Heethaar ◽  
JJ Sixma

Abstract The hematocrit is one of the main factors influencing platelet adherence to the vessel wall. Raising the hematocrit causes an increase of platelet accumulation of about an order of magnitude. Our studies concern the role of red cell size. We have studied this effect using an annular perfusion chamber, according to Baumgartner, with human umbilical arteries and a steady-flow system. Normal human red blood cells (MCV 95 cu mu) increased platelet adherence sevenfold, as the hematocrit increases from 0 to 0.6. Small erythrocytes from goats (MCV 25 cu mu) caused no increment in adherence in the same hematocrit range. Rabbit erythrocytes (MCV 70 cu mu) caused an intermediate increase in adherence. Red blood cells from newborns (MCV 110–130 cu mu) caused a larger increase in platelet adherence than normal red cells at hematocrit 0.4. These results were further confirmed with large red blood cells from two patients. Experiments with small red cells (MCV 70 cu mu) of patients with iron deficiency showed that platelet adherence was similar to normal red cells, provided the red cell diameter was normal. Small red blood cells of a patient with sideroblastic anemia caused decreased adherence. These data indicate that red cell size is of major importance for platelet adherence. Red cell diameter is more important than average volume. However, for size differences in the human range, the hematocrit remains the dominant parameter.


Blood ◽  
1955 ◽  
Vol 10 (4) ◽  
pp. 370-376 ◽  
Author(s):  
HANS G. KEITEL ◽  
H. BERMAN ◽  
H. JONES ◽  
E. MACLACHLAN

Abstract 1. Red cells from different layers of centrifuged cells vary in composition. Cells obtained from the upper layer, which is relatively richer in reticulocytes, contain more water, sodium, potassium, chloride and phosphorus than the remaining cells. 2. The direct method of analysis of red blood cells using a constricted type centrifuge tube to separate the entire red cells sample from buffy layer cells and from plasma avoids the errors in direct analysis caused by different cell population in upper and lower layers of centrifuged cells and the cumulative errors inherent in indirect analysis. 3. Using the direct method and a constricted type centrifuge tube, the means and standard deviations of the water and mineral content of the erythrocytes and plasma of 11 normal males and 11 normal females were determined. Males were found to have a higher sodium content of red cells and plasma. 4. The sum of the molal concentrations of sodium, potassium, chloride and phosphorus in red cells is not always equal to the sum of the molal concentrations of these minerals in the plasma.


1977 ◽  
Vol 69 (1) ◽  
pp. 75-96 ◽  
Author(s):  
Z I Cabantchik ◽  
H Ginsburg

The kinetic properties of the mediated transport of uridine in human erythrocytes are investigated. Different methodological procedures are use to acquire a complete kinetic description of the system...


Blood ◽  
1983 ◽  
Vol 62 (1) ◽  
pp. 214-217 ◽  
Author(s):  
PA Aarts ◽  
PA Bolhuis ◽  
KS Sakariassen ◽  
RM Heethaar ◽  
JJ Sixma

The hematocrit is one of the main factors influencing platelet adherence to the vessel wall. Raising the hematocrit causes an increase of platelet accumulation of about an order of magnitude. Our studies concern the role of red cell size. We have studied this effect using an annular perfusion chamber, according to Baumgartner, with human umbilical arteries and a steady-flow system. Normal human red blood cells (MCV 95 cu mu) increased platelet adherence sevenfold, as the hematocrit increases from 0 to 0.6. Small erythrocytes from goats (MCV 25 cu mu) caused no increment in adherence in the same hematocrit range. Rabbit erythrocytes (MCV 70 cu mu) caused an intermediate increase in adherence. Red blood cells from newborns (MCV 110–130 cu mu) caused a larger increase in platelet adherence than normal red cells at hematocrit 0.4. These results were further confirmed with large red blood cells from two patients. Experiments with small red cells (MCV 70 cu mu) of patients with iron deficiency showed that platelet adherence was similar to normal red cells, provided the red cell diameter was normal. Small red blood cells of a patient with sideroblastic anemia caused decreased adherence. These data indicate that red cell size is of major importance for platelet adherence. Red cell diameter is more important than average volume. However, for size differences in the human range, the hematocrit remains the dominant parameter.


1976 ◽  
Vol 31 (3-4) ◽  
pp. 149-151 ◽  
Author(s):  
Dieter Auer ◽  
Gerhard Brandner

Abstract Human erythrocytes were suspended in Hank’s solution containing mammalian or viral DNA or RNA. After dialysis at 0 °C first against water and subsequently against Hank’s solution, and a further incubation at 37 °C , the erythrocytes were found to be loaded with the nucleic acids. The nucleic acid trapped in the erythrocytes exhibited up to 35 per cent of the external concentration.


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