PRODUCTION OF ANTISERA TO NORMAL HUMAN ERYTHROCYTES COATED WITH INCOMPLETE SPECIFIC ANTIBODIES AND BOUND COMPLEMENT (EAC‘)

2009 ◽  
Vol 56 (3) ◽  
pp. 335-340
Author(s):  
Harald Örjasaeter
Blood ◽  
1995 ◽  
Vol 86 (5) ◽  
pp. 1983-1991 ◽  
Author(s):  
EM Bevers ◽  
T Wiedmer ◽  
P Comfurius ◽  
J Zhao ◽  
EF Smeets ◽  
...  

Elevation of cytoplasmic Ca2+ levels in human erythrocytes induces a progressive loss of membrane phospholipid asymmetry, a process that is impaired in erythrocytes from a patient with Scott syndrome. We show here that porcine erythrocytes are similarly incapable of Ca(2+)- induced redistribution of membrane phospholipids. Because a complex of phosphatidylinositol 4,5-bisphosphate (PIP2) and Ca2+ has been proposed as the mediator of enhanced transbilayer movement of lipids (J Biol Chem 269:6347,1994), these cell systems offer a unique opportunity for testing this mechanism. Analysis of both total PIP2 content and the metabolic-resistant pool of PIP2 that remains after incubation with Ca2+ ionophore showed no appreciable differences between normal and Scott erythrocytes. Moreover, porcine erythrocytes were found to have slightly higher levels of both total and metabolic-resistant PIP2 in comparison with normal human erythrocytes. Although loading of normal erythrocytes with exogenously added PIP2 gave rise to a Ca(2+)-induced increase in prothrombinase activity and apparent transbilayer movement of nitrobenzoxadiazolyl (NBD)-phospholipids, these PIP2-loaded cells were also found to undergo progressive Ca(2+)-dependent cell lysis, which seriously hampers interpretation of these data. Moreover, loading Scott cells with PIP2 did not abolish their impaired lipid scrambling, even in the presence of a Ca(2+)-ionophore. Finally, artificial lipid vesicles containing no PIP2 or 1 mole percent of PIP2 were indistinguishable with respect to transbilayer movement of NBD- phosphatidylcholine in the presence of Ca2+. Our findings suggest that Ca(2+)-induced redistribution of membrane phospholipids cannot simply be attributed to the steady-state concentration of PIP2, and imply that such lipid movement is regulated by other cellular processes.


1975 ◽  
Vol 49 (5) ◽  
pp. 375-384
Author(s):  
N. Worathumrong ◽  
A. J. Grimes

1. Some effects of sodium salicylate upon anaerobic glycolysis have been studied in normal human erythrocytes incubated for up to 6 h at 37°C in autologous sera. 2. Both glucose consumption and lactate production were stimulated by concentrations of salicylate up to 60 mmol/l but at the highest concentration used (90 mmol/l) an initial stimulus was followed by inhibition of glycolysis. 3. Losses occurred of adenosine 5′-triphosphate (ATP), adenosine 5′-diphosphate (ADP) and adenosine 5′-phosphate (AMP) at higher concentrations of salicylate and there was a concomitant increase of inorganic phosphate. 4. Other phosphate esters underwent concentration changes at higher concentrations of salicylate that reflected inadequate concentrations of ATP for glycolysis. 5. The rates of sodium efflux from, and potassium influx into, erythrocytes were unaffected by the presence of salicylate at concentrations sufficient to stimulate glycolysis.


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.


Vox Sanguinis ◽  
1984 ◽  
Vol 47 (2) ◽  
pp. 146-156
Author(s):  
Parviz Lalezari ◽  
An Fu Jiang

1970 ◽  
Vol 132 (5) ◽  
pp. 898-915 ◽  
Author(s):  
Otto Götze ◽  
Hans J. Müller-Eberhard

A new pathway of complement-mediated hemolysis has been described. It is independent of antibody and does not require binding of the first four complement components to the target-cell surface. The actual attack of the target cell begins with the attachment of C5, C6, and C7. The binding reaction is catalyzed by C4, 2, 3, an enzyme which may be formed in cell-free solution. C4, 2, 3 may effect binding of C5, 6, 7 by acting from the fluid phase or from the surface of another cell to which it is specifically bound (EAC 4, 2, 3). In either case, the resulting product is EC5, 6, 7 which is susceptible to lysis by C8 and C9. Erythrocytes from patients with paroxysmal nocturnal hemoglobinuria (PNH) were particularly susceptible to lysis by the above described mechanism. PNH cells, but not normal human erythrocytes, could also be lysed through activation of complement by cobra factor. These observations allow the operational distinction of an activation and an attack mechanism of complement.


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.


1982 ◽  
Vol 60 (1) ◽  
pp. 52-59 ◽  
Author(s):  
S. Rowlands ◽  
L. S. Sewchand ◽  
E. G. Enns

Theory predicts that the membrane potential will polarize membrane molecules and cause them to vibrate coherently at a frequency of ~ 1011 Hz. If the supply of metabolic energy exceeds a minimum value, membrane phonons may condense their momentum into a single "giant" vibrational mode. At 1011 Hz ionic screening is small up to distances of approximately a micrometre, so forces of a range several orders of magnitude longer than chemical forces can arise. These forces may be attractive or repulsive depending on frequency. They should occur in every metabolically active membrane and may control macromolecular transport and enzyme–substrate interactions. We find that normal human erythrocytes in plasma form rouleaux faster than Brownian motion predicts. When cells are fixed in glutaraldehyde or are metabolically depleted, or if the membrane potential is brought to zero, the rate of aggregation agrees with Brownian theory. When the metabolically depleted cells are revived or if the membrane potential is restored, then the interaction returns.


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