The calcium content of human erythrocytes

Harrison, David G.; Long, Cheryl

doi:10.1113/jphysiol.1968.sp008658

Cited by 172 publications

(74 citation statements)

References 16 publications

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“…T C a 2 + content or the wash solutions was negligible. which indica~ minimal contamination of washed red cells with trapped plasm The Ca2' content of ghosts was identical with that of whole R B confirming the observations of Harrison and Long (12). Kno) concentrations of Ca2' were subjected to the extraction proct and recovery was found to be complete.…”

Section: Methodssupporting

confidence: 69%

“…The clinical severity of hemolysis was quite similar in all H S patients examined while the observed C a 2 + content in each study group was variable. The variability of erythrocyte C a 2 + content has been noted by several other groups (6,12,18). Even though a few patients with H S had red cell C a 2 + values within the normal range, no correlation was possible between the clinical severity of hemolytic anemia in a given patient, and the Ca2+ content of that patient's RBC.…”

Section: Discussionmentioning

confidence: 81%

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Increased Erythrocyte Ca2+ Content in Hereditary Spherocytosis

Feig¹,

Bassilian²

1975

Pediatr Res

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P e d i a t . Res. 9: 928-931 (1975) A T P a s e hereditary spherocyt e r y t h r o c y t e splenectomy ExtractThe C a 2 + content of red blood cells ( R B C ) appears to correlate inversely with the Ca2--ATPase activity of the red cell membrane (Fig. 1 ). When hereditary spherocytosis H S ) cells and normal control erythrocytes are compared, the dependence of Ca2+ content upon ATPase activity is similar. The C a 2 + content of H S red cells is increased compared with appropriate control erythrocytes matched for cell age (Fig. 2). Splenectomv has a different effect upon H S cells than upon normal cells (Fig. 2). Erythrocytes of splenectomized patients with H S seem to contain less C a 2 + than d o those of presplenectomy patients with H S. whereas the reverse appears to pertain in normal subjects. SpeculationThe control of RBC C a 2 + content is complex. Although there may be some dependence upon Ca2+-ATPase, other factors are intolted. The splenic environment may be particularly unfavorahle for the extrusion of Ca2+ from the H S red cell, thus leading to excessi~e accumulation of Ca2+ and further impairment of RBC membrane function in the splenic milieu. This process may play a fundamental role in the pathogenesis of hemolysis in hereditary spherocytosis.Hereditary spherocytosis is thought to be the result of an intrinsic abnormality of the red cell membrane protein. The impaired deformability (16) and reduced capacity to form endocytic vacuoles (3) observed in that syndrome might be explained by an altered interaction of the RBC membrane with C a 2 + .A relative deficiency of membrane Ca2+dependent adenosine triphosphatase (Ca2+-ATPase) in H S ghosts has been described previously (7). This observation might be related to the pathogenesis of the H S defect in several ways. There is evidence which suggests that membrane Ca2+-ATPase may he linked with the active transport of Ca" from the red cell (17. 27). Furthermore, elevation of red cell Ca2+ content is associated with impaired membrane deformability (31). and impaired endocytic vacuole formation (3) in normal RBC.These studies were undertaken in an attempt to determine whether an increase in erythrocyte Ca2+ content was present in H S cells and how this might relate to the pathogenesis of HS. PATIENT SELECTIONPatients were selected from the clinical services of the Departments of Medicine and Pediatrics of the UCLA Center for the Health Sciences. The diagnosis of H S was made on the basis of characteristic morphology, family history, and typical pattern5 of autohemolysis and osmotic fragility. Normal control subjects were selected from the clinical, laboratory. and secretarial staffs of the hospital. High reticulocyte control specimens were obtained from patients with acquired autoimmune hemolytic anemia (two patients), hypersplenism (one). and patients recovering from pernicious anemia (one). and from iron deficiency anemia (01 Splenectomized control subjects were all patients with Hodgk, disease who had previously undergone staging laparotoniy. Nl of th...

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Section: Methodssupporting

confidence: 69%

Section: Discussionmentioning

confidence: 81%

Increased Erythrocyte Ca2+ Content in Hereditary Spherocytosis

Feig¹,

Bassilian²

1975

Pediatr Res

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“…The whole blood was centrifuged at 2500 g for 5 min and the plasma and buffy coat aspirated. The red cells were then washed 5 times at 10-20 'C in at least five volumes of medium A, 100 /sM-EGTA being included in the medium during the first two washes to remove externally bound Ca from the cells (Harrison & Long, 1968;Bookchin & Lew, 1980). At each wash, care was taken to remove all traces of white cells.…”

Section: Preparation Of Cellsmentioning

confidence: 99%

The effect of intracellular calcium on the sodium pump of human red cells.

Brown¹,

Lew²

1983

The Journal of Physiology

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SUMMARY1. The inhibitory effect of cytoplasmic Ca on Na-pump-mediated Na-K exchange was investigated in intact red cells under conditions of constant cell volume, membrane potential and inorganic ion composition. The ionized cytoplasmic Ca concentration ([Ca2+]1) was controlled using the ionophore A23187.2. In normal cells, ouabain-sensitive 24Na efflux was inhibited with an apparent affinity for [Ca2+], which depended on the concentration of A23187; 50 % inhibition required 20-40 fM and 160-300 LM-cytoplasmic Ca2+ with 10 /tM and 0-63 SM-A23187 respectively. Cytoplasmic Ca also affected cell ATP content which fell rapidly on addition of A23187 and subsequently increased, steadied or continued to fall more slowly depending on the Ca and A23187 concentrations. Half-maximal fall required 5-15 AM and 110-170 /tM-cytoplasmic Ca2+ at 10/M and 0-63 /M-A23187 respectively.Removal of Ca from the cells failed to reverse either the Na pump inhibition or the fall in cell ATP.3. In ATP-enriched cells cytoplasmic Ca caused inhibition of ouabain-sensitive 24Na efflux in an A23187-dependent manner with apparent affinities for [Ca2+], similar to those observed in the normal cells. Inhibition was complete at high [Ca2+],. As in the normal cells, the ATP content of the cells fell in the presence of cytoplasmic Ca, but always remained above 1-2 m-mole/l. cells. This was higher than the ATP content of Ca-free normal intact cells. 4. A23187 had no effect on the inhibition by Ca of ouabain-sensitive ATPase activity in isolated red cell membrane preparations. Both under conditions near optimal for Na-K-ATPase activity and under conditions resembling those in the cytoplasm, inhibition was half-maximal at about 25 um-Ca2+ and in the latter case complete at below 400 /tM-Ca2 .5. The apparent ATP-dependence of ouabain-sensitive Na efflux in the presence of cytoplasmic Ca was distinctly different in the normal and ATP-enriched cells but in both groups of cells it was similar for data obtained with high and low concentrations of A23187.6. The data for Na pump inhibition by cytoplasmic Ca in the intact cells were well fitted by several kinetic models involving either [Ca2+], or CaATP as the inhibitory species and a low affinity dependence of pump activity on MgATP or total ATP. A. M. BROWN AND V. L. LEWHowever, for any model, the apparent affinities for CaATP or for Ca2+ required to fit the ATPase data were 25-10 times higher than those required to fit the data for Na efflux. 7. From the kinetic models fitted to the Na efflux data, it is predicted that physiological (i.e. 1-10 #m) fluctuations in cell [Ca2+], will inhibit the Na pump by less than 35 %.

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“…Triple-glass-distilled water was used throughout; it was calcium-free. The calcium analytical standard for atomic-absorption spectrophotometry was described by Harrison & Long (1968).…”

Section: Methodsmentioning

confidence: 99%

The influx of calcium ions into human erythrocytes during cold storage. The influences of extracellular pH, intracellular adenosine triphosphate and efflux of univalent cations

Mouat

Long

1974

Biochemical Journal

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1. When human erythrocytes are stored at 3°C for several days as a suspension in isoosmotic sucrose or KCI, containing CaCl2, the rates of cellular ATP degradation are similar. 2. During cold storage oferythrocytes in sucrose-CaCl2 medium, Ca2+ influx and univalent-cation efflux occur, the pH value of the suspending medium rises and the intracellular pH falls. These pH changes correlate reasonably well with alterations in the membrane potential calculated from Cl-distribution. 3. The presence of Ca2+ in the medium does not increase the rate of univalent-cation efflux from the cells. 4. When the pH of the medium is raised by addition of buffers, the rates of both Ca2+ influx and univalent-cation efflux increase. 5. Replacement of sucrose by KCI as the main osmotic component of the medium completely suppresses Ca2+ influx and univalent-cation efflux, although the pH of the KCI medium is higher than that of the sucrose medium. 6. When sucrose is replaced by choline chloride, Ca2+ influx and univalent-cation efflux still occur, and the pH of the medium is similar to that found in iso-osmotic KCI. 7. When valinomycin, Pb2+ or Cd2+ are added to the iso-osmotic sucrose medium, the rate of efflux of univalent cations increases as also does the influx of Ca2+. 8. From these and other observations, it was concluded that it is univalent-cation efflux rather than ATP depletion or elevated extracellular pH which is the prerequisite for Ca2+ influx during cold storage.

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The calcium content of human erythrocytes

Cited by 172 publications

References 16 publications

Increased Erythrocyte Ca2+ Content in Hereditary Spherocytosis

Increased Erythrocyte Ca2+ Content in Hereditary Spherocytosis

The effect of intracellular calcium on the sodium pump of human red cells.

The influx of calcium ions into human erythrocytes during cold storage. The influences of extracellular pH, intracellular adenosine triphosphate and efflux of univalent cations

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