Calcium Transport and the Properties of a Calcium-Activated Potassium Channel in Red Cell Membranes

Lew, Virgilio L.; Ferreira, H. G.

doi:10.1016/s0070-2161(08)60836-9

Cited by 187 publications

(125 citation statements)

References 73 publications

Supporting

Mentioning

117

Contrasting

Order By: Relevance

“…Table 1 shows that the bumetanide-resistant component of potassium transport which is stimulated by calcium is completely inhibited by 1 mm-quinine. In this respect the calcium-activated potassium transporter in ferret red cells is similar to the calcium-activated potassium transporter in other animals' red cells (see Lew & Ferreira, 1978).…”

Section: Control Of Intracellular Magnesium and Calcium By A23187mentioning

confidence: 57%

The effects of calcium on potassium transport in ferret red cells.

Flatman

1987

The Journal of Physiology

View full text Add to dashboard Cite

1. The effects of changes in the concentration of intracellular calcium on potassium transport were investigated in ferret red cells. Bumetanide was used to divide potassium transport into three components: total, bumetanide sensitive and bumetanide resistant. The bumetanide‐sensitive component is equivalent to sodium‐potassium‐chloride co‐transport. 2. Internal calcium concentration was controlled with the ionophore A23187 which was present throughout the experiments. 3. Changes in internal ionized calcium over the range 5 X 10(‐10) M to 7 X 10(‐7) M did not affect any component of potassium uptake. 4. Increasing the internal ionized calcium concentration above 10(‐6) M stimulated bumetanide‐resistant potassium transport. Half‐maximal stimulation of this system was achieved with 3 X 10(‐6) M‐internal calcium. The system spontaneously inactivated after the initial activation by calcium and ionophore. Transport was inhibited by 1 mM‐quinine. 5. Increasing the internal ionized calcium concentration to 10(‐5) M had no effect on bumetanide‐sensitive transport. 6. Concentrations of intracellular ionized calcium above 10(‐5) M inhibited all three components of transport. Inhibition of the bumetanide‐sensitive component was only slightly reversed when internal calcium concentration was reduced to normal. 7. Physiological changes in internal ionized calcium concentration do not affect sodium‐potassium‐chloride co‐transport in ferret red cells. Very high concentrations of calcium inhibit transport, probably by an indirect mechanism. 8. In the course of the experiments the concentration of ionized intracellular magnesium in oxygenated ferret red cells was found to be about 0.65 mM.

show abstract

Section: Control Of Intracellular Magnesium and Calcium By A23187mentioning

confidence: 57%

The effects of calcium on potassium transport in ferret red cells.

Flatman

1987

The Journal of Physiology

View full text Add to dashboard Cite

show abstract

“…In the case of enucleated erythrocytes, low cytoplasmic Ca' concentrations are achieved by a combination of plasma membrane Ca" binding, low membrane Ca' permeability, and active extrusion by Ca 2+' Mg t +-ATPase pump (1,2). Elevation of intracellular Ca 2+ results in decreased membrane deformability, altered monovalent cation transport, and modification of membrane protein structure, e.g .…”

mentioning

confidence: 99%

“…Elevation of intracellular Ca 2+ results in decreased membrane deformability, altered monovalent cation transport, and modification of membrane protein structure, e.g . spectrin degradation (1,3) . Malaria is a blood-borne disease in which the asexual development of the parasite Plasmodium occurs within the host erythrocyte.…”

mentioning

confidence: 99%

Calcium transport of Plasmodium chabaudi-infected erythrocytes.

Tanabe¹,

Mikkelsen²,

Wallach³

1982

The Journal of Cell Biology

118

View full text Add to dashboard Cite

The calcium content and transport processes of Plasmodium chabaudi-infected rat erythrocytes were analyzed by atomic absorption spectroscopy and "Ca" flux measurements . Infected erythrocytes, after fractionation on metrizamide gradients according to stage of parasite development, exhibited progressively increasing levels of Ca 2+ with schizont and gametocytes containing 10-to 20-fold greater calcium levels than normal cells (0.54 ± 0.25 nmol/108 cells) . 45Ca 2 + flux experiments showed both increased influx and decreased efflux in infected erythrocytes . Tris/NH 4C1 lysis of normal erythrocytes preloaded with 45 Ca 2+ with the Ca 2+ ionophore A23187 released >90% of cell calcium after incubation in ethyleneglycol bis(aminoethylether) N, N'-tetraacetic acid containing buffer, whereas lysis of the infected erythrocyte membrane resulted in release of 10-20% cell Cat+ , with the remaining portion associated with the isolated parasite fraction . This information together with the effects of various metabolic inhibitors indicates the presence of a parasite Ca' compartment in P. chabaudi-infected erythrocytes .Dicyclohexylcarbodiimide (DCCD) an inhibitor of proton ATPases of chloroplasts, bacteria, yeast, and mitochondria, and the proton ionophore, carbonyl cyanide m-chlorophenylhydrazone (CCCP), inhibited Ca 2+ influx and stimulated efflux from infected cells . These results combined with evidence for a DCCD-and CCCP-sensitive membrane potential in P. chabaudiinfected cells (Mikkelsen et al ., accompanying manuscript) suggest that Ca 2+ transport of intraerythrocytic parasites is coupled to a proton-motive force across the Plasmodia plasma membrane .The calcium ion is an essential component of many cellular regulatory processes, and cells expend considerable energy to maintain low levels of free cytoplasmic Cat+ . In the case of enucleated erythrocytes, low cytoplasmic Ca' concentrations are achieved by a combination of plasma membrane Ca" binding, low membrane Ca' permeability, and active extrusion by Ca 2+' Mg t +-ATPase pump (1, 2). Elevation of intracellular Ca 2+ results in decreased membrane deformability, altered monovalent cation transport, and modification of membrane protein structure, e.g . spectrin degradation (1, 3) . Malaria is a blood-borne disease in which the asexual development of the parasite Plasmodium occurs within the host erythrocyte. Few investigators have addressed the general issue of ion transport in Plasmodium-infected erythrocytes, although increased osmotic fragility is a common observation of Plasmodium-infected erythrocytes . Dunn (4) has shown increased sodium and decreased potassium intracellular levels resulting in part from decreased Na', K+-ATPase activity of parasitized erythrocytes . No information is available concerning Ca" levels and intracellular Ca" distribution in infected cells or the relative contributions of erythrocyte and parasite Ca' transport processes of infected cells. Such information may indicate mechanisms by which the parasite modifies its intracellu...

show abstract

“…6,16,17 What this study adds K ADD2 1797CC homozygous men exhibit slightly lower concentrations of intra-erythrocyte potassium, higher magnesium but similar sodium compared with T-allele carriers. K In 136 women, none of the phenotype-genotype relations reached significance.…”

mentioning

confidence: 71%

“…Opening of the channel increases K þ efflux through the membrane by three orders of magnitude. 16,17 Magnesium inhibits the opening of the Gardos channel. Intra-erythrocyte magnesium represents only 0.5% of the total body content of magnesium.…”

Section: Discussionmentioning

confidence: 99%

Intra-erythrocyte cation concentrations in relation to the C1797T β-adducin polymorphism in a general population

et al. 2007

View full text Add to dashboard Cite

Genetic variability in the ADD1 (Gly460Trp) and ADD2 (C1797T) subunits of the cytoskeleton protein adducin plays a role in the pathogenesis of hypertension, possibly via changes in intracellular cation concentrations. ADD2 1797CC homozygous men have decreased erythrocyte count and hematocrit. We investigated possible association between intra-erythrocyte cations and the adducin polymorphisms. In 259 subjects (mean age 47.7 years), we measured intra-erythrocyte Na, serum cations and adducin genotypes. Genotype frequencies (ADD1: GlyGly 61.5%, Trp 38.5%; ADD2: CC 80.4%, T 19.6%) complied with Hardy-Weinberg proportions. In men, ADD2 CC homozygotes (n ¼ 100) compared to T-carriers (n ¼ 23) had slightly lower iK (85.8 versus 87.5 mmol/l cells; P ¼ 0.107), higher iMg (1.92 versus 1.80 mmol/l cells; P ¼ 0.012), but similar iNa (6.86 versus 6.88 mmol/l cells; P ¼ 0.93). In men, iK, iMg and iNa did not differ according to ADD1 genotypes. In men, iK (R 2 ¼ 0.128) increased with age and serum Na þ , but decreased with serum total calcium and the daily intake of alcohol. iMg (R 2 ¼ 0.087) decreased with age, but increased with serum total calcium. After adjustment for these covariates (Pp0.04 for all), findings in men for iK (CC versus T: 85.8 versus 87.3 mmol/l; P ¼ 0.14) and iMg (1.91 versus 1.82 mmol/l; P ¼ 0.03) remained consistent. In 136 women, none of the phenotype-genotype relations reached significance. Changes in intra-erythrocyte cations in ADD2 1797CC homozygous men might lead to osmotic fragility of erythrocytes, but to what extent they reflect systemic changes or are possibly involved in blood pressure regulation remains unknown.

show abstract

Calcium Transport and the Properties of a Calcium-Activated Potassium Channel in Red Cell Membranes

Cited by 187 publications

References 73 publications

The effects of calcium on potassium transport in ferret red cells.

The effects of calcium on potassium transport in ferret red cells.

Calcium transport of Plasmodium chabaudi-infected erythrocytes.

Intra-erythrocyte cation concentrations in relation to the C1797T β-adducin polymorphism in a general population

Contact Info

Product

Resources

About