Action of cetiedil citrate on the cation content, deformability, and osmotic fragility of human erythrocytes

2018 ◽  
Vol 8 (5) ◽  
pp. 649-661 ◽  
Author(s):  
Y.Y. Bilto ◽  
M. Player ◽  
J. Stuart
1987 ◽  
Vol 252 (3) ◽  
pp. C269-C276 ◽  
Author(s):  
C. Brugnara ◽  
D. C. Tosteson

We report here studies on the regulation of cell volume and K transport in human erythrocytes separated according to density. When cell volume was increased (isosmotic swelling, nystatin technique), erythrocytes of the least dense but not of the densest fraction shrunk back toward their original volume. This process was due to a ouabain (0.1 mM) and bumetanide (0.01 mM) (OB)-resistant K loss. OB-resistant K+ efflux from the least dense fraction was stimulated by hypotonic swelling and had a bell-shaped dependence on pH (pH optimum 6.75–7.0). These pH and volume effects were not evident in the densest fraction. The swelling-induced K+ efflux from the least dense fraction was inhibited when chloride was substituted by nitrate, thiocyanate, and acetate, whereas it was stimulated by bromide. Increasing cell Mg2+ content also markedly inhibited K+ efflux from isosmotically swollen cells. N-ethylmaleimide (NEM, 1 mM) greatly increased OB-resistant K+ efflux from the least dense fraction but not from the densest fraction. These data reveal the presence, in the lease dense fraction of normal human erythrocytes, of a pathway for K+ transport that is dependent on volume, pH, and chloride, is inhibited by internal Mg2+, and possibly plays a role in determining the erythrocyte water and cation content.


1986 ◽  
Vol 234 (3) ◽  
pp. 649-652 ◽  
Author(s):  
G Mallinson ◽  
P G Martin ◽  
D J Anstee ◽  
M J A Tanner ◽  
A H Merry ◽  
...  

Rhnull human erythrocytes lack the antigens of the Rhesus blood-group system, have an abnormal shape, have an increased osmotic fragility, and are associated with mild chronic haemolytic anaemia. Rhnull erythrocytes also lack all antigens of the LW blood-group system, but the functional significance of this deficiency is unknown. We have identified, by immunoblotting with two mouse monoclonal antibodies (BS46 and BS56), the LW-active component(s) in normal human erythrocytes as a broad band of Mr 37 000-47 000 on SDS/polyacrylamide-gel electrophoresis. Treatment of intact human erythrocytes with endoglycosidase F preparation destroyed the epitopes recognized by antibodies BS46 and BS56, suggesting that one or more N-glycosidically linked oligosaccharides are required for the formation of the LW antigens. Estimation of the number of LW antigen sites per erythrocyte by using radioiodinated purified antibody BS46 gave average values of 4400 molecules/cell for Rh(D)-positive adult erythrocytes and 2835 molecules/cell for Rh(D)-negative adult erythrocytes. Like the Rh(D) polypeptide, the LW polypeptide(s) is (are) associated with the cytoskeleton of normal erythrocytes. These results suggest the possibility that the absence of the LW polypeptide may also contribute to the functional and/or morphological abnormalities of Rhnull erythrocytes.


2014 ◽  
Vol 38 (5) ◽  
pp. 625-630 ◽  
Author(s):  
Julio C. M. Soares ◽  
Vanderlei Folmer ◽  
João B. T. Da Rocha ◽  
Cristina W. Nogueira

1983 ◽  
Vol 222 (2) ◽  
pp. 582-589 ◽  
Author(s):  
Joseph M. Rifkind ◽  
Koji Araki ◽  
Evan C. Hadley

Blood ◽  
1981 ◽  
Vol 58 (2) ◽  
pp. 317-325
Author(s):  
RA Streuli ◽  
JR Kanofsky ◽  
RB Gunn ◽  
S Yachnin

Oxygenated sterol compounds (OSC), when incubated for 1 hr with human erythrocytes in lipoprotein-depleted medium at concentrations of 0.625- 5 X 10(-5) M, are inserted into the cell membrane and remain there despite subsequent washing of the cells. The insertion results in expansion of the surface area of the red cell ghost membrane, an increase in critical hemolytic volume, and as a consequence, in diminished osmotic fragility of the erythrocytes. This effect is seen with echinocyte-forming as well as with non-echinocyte-forming OSC. Erythrocytes treated with OSC do not differ from control cells with respect to their mean cell volume (MCV) in isotonic solution, water content, ion fluxes, and filterability through polycarbonate filters. The shift of the osmotic fragility curve toward lower NaCl concentrations is proportional to the amount of OSC inserted into the red cell membrane. 7 beta-Hydroxycholesterol, 22-ketocholesterol, and 20 alpha-hydroxycholesterol are the most potent inhibitors of osmotic lysis. The effect of OSC on osmotic fragility is diminished if the erythrocytes are incubated in a lipoprotein-containing medium; free cholesterol, however, does not change this effect. Various progesterones also protect red cell from osmotic lysis, but only if the erythrocytes are directly exposed to the compounds present in the hypotonic NaCl solutions used for measurement of their osmotic fragility. Progesterones do not remain in the membrane after the cells have been washed. The OSC are also capable of correcting the osmotic fragility curve of red cells from patients with hereditary spherocytosis. These experiments may suggest an approach to the pharmacologic treatment of hereditary spherocytosis.


Blood ◽  
1984 ◽  
Vol 63 (5) ◽  
pp. 1046-1055 ◽  
Author(s):  
SK Ballas ◽  
MR Clark ◽  
N Mohandas ◽  
HF Colfer ◽  
MS Caswell ◽  
...  

Abstract A 52-yr-old multiparous white female was found to have Rh null blood type. She had macrocytic anemia, with reticulocytosis (15%-20%), of long duration. Although stomatocytes in peripheral blood were numerous and osmotic fragility was increased, suggesting increased cell water, the RBC cation content, and thus cell water, was decreased. Cell dehydration was confirmed by an increased proportion of high density RBC on Stractan density gradients. The deformability of RBC from four gradient subpopulations was measured in the ektacytometer as a function of suspending medium osmolality. Analysis of these measurements showed an abnormal reduction in cell surface area with increasing cell density, thus explaining the increased osmotic fragility of whole blood. This was confirmed by a density-dependent reduction in cell cholesterol content, suggesting membrane instability in vivo. Rh null subpopulations showed a twofold increase in both ouabain-sensitive and - insensitive Na-K ATPase activity and 86Rb transport, even in the dense fraction with the fewest reticulocytes. No membrane protein or glycoprotein abnormality was detected by SDS-PAGE. The associated deficiencies of both membrane surface area and cation content in Rh null cells, as well as increased Na-K pump activity, suggest a pleiotropic functional interrelationship among Rh antigen, membrane stability, and cation regulation.


Blood ◽  
1981 ◽  
Vol 58 (2) ◽  
pp. 317-325 ◽  
Author(s):  
RA Streuli ◽  
JR Kanofsky ◽  
RB Gunn ◽  
S Yachnin

Abstract Oxygenated sterol compounds (OSC), when incubated for 1 hr with human erythrocytes in lipoprotein-depleted medium at concentrations of 0.625- 5 X 10(-5) M, are inserted into the cell membrane and remain there despite subsequent washing of the cells. The insertion results in expansion of the surface area of the red cell ghost membrane, an increase in critical hemolytic volume, and as a consequence, in diminished osmotic fragility of the erythrocytes. This effect is seen with echinocyte-forming as well as with non-echinocyte-forming OSC. Erythrocytes treated with OSC do not differ from control cells with respect to their mean cell volume (MCV) in isotonic solution, water content, ion fluxes, and filterability through polycarbonate filters. The shift of the osmotic fragility curve toward lower NaCl concentrations is proportional to the amount of OSC inserted into the red cell membrane. 7 beta-Hydroxycholesterol, 22-ketocholesterol, and 20 alpha-hydroxycholesterol are the most potent inhibitors of osmotic lysis. The effect of OSC on osmotic fragility is diminished if the erythrocytes are incubated in a lipoprotein-containing medium; free cholesterol, however, does not change this effect. Various progesterones also protect red cell from osmotic lysis, but only if the erythrocytes are directly exposed to the compounds present in the hypotonic NaCl solutions used for measurement of their osmotic fragility. Progesterones do not remain in the membrane after the cells have been washed. The OSC are also capable of correcting the osmotic fragility curve of red cells from patients with hereditary spherocytosis. These experiments may suggest an approach to the pharmacologic treatment of hereditary spherocytosis.


2009 ◽  
Vol 25 (8) ◽  
pp. 545-550 ◽  
Author(s):  
Ismail Karabulut ◽  
Z. Dicle Balkanci ◽  
Bilge Pehlivanoglu ◽  
Aysen Erdem ◽  
Ersin Fadillioglu

Toluene, an organic solvent used widely in the industry, is highly lipophilic and accumulates in the cell membrane impeding transport through it. Its metabolites cause oxygen radical formation that react with unsaturated fatty acids and proteins in erythrocytes leading to lipid peroxidation and protein breakdown. In this study, we aimed to investigate the membrane stabilizing and the oxidative stress—inducing effects of toluene in human erythrocytes. Measurements of osmotic fragility, mean corpuscular volume (MCV), oxidative stress parameters and antioxidant enzyme activities were performed simultaneously both in individuals exposed to toluene professionally (in vivo) and human erythrocytes treated with toluene (in vitro). To measure osmotic fragility, erythrocytes were placed in NaCl solutions at various concentrations (0.1% [blank], 0.38%, 0.40%, 0.42%, 0.44%, 0.46%, 0.48% and 1% [stock]). Percentage of haemolysis in each solution was calculated with respect to the 100% haemolysis in the blank solution. The erythrocyte packs prepared at the day of the above-mentioned measurements were kept at —80°C until the time for determination of malonyldialdehyde and protein carbonyl levels, and catalase (CAT) and glutathione peroxidase activities as indicators of oxidative stress. Toluene increased oxidative stress parameters significantly both in vivo and in vitro; it also caused a significant decrease in the activities of antioxidant enzymes. Osmotic fragility was altered only in the case of in vitro exposure. In conclusion, toluene exposure resulted in increased lipid peroxidation and protein damage both in vivo and in vitro. Although, it is natural to expect increased osmotic fragility due to oxidative properties of toluene, its membrane-stabilizing effect overcame the oxidative properties leading to decreased osmotic fragility or preventing its deterioration in vitro and in vivo toluene exposures, respectively, in the present study.


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