CELL VOLUME REGULATION BY MOLLUSCAN ERYTHROCYTES DURING HYPOOSMOTIC STRESS: Ca<sup>2+</sup>EFFECTS ON IONIC AND ORGANIC OSMOLYTE EFFLUXES

Smith, Laurens H.; Pierce, Sidney K.

doi:10.2307/1541553

Cited by 28 publications

(15 citation statements)

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“…One of the more common intracellular solutes participating in cell volume regulation is K'. Net K+ loss in response to hypo-osmotic stress occurs in red blood cells of many species (e.g., Dickman and Goldstein, 1990;Bourne and Cossins, 1984;Berkowitz and Orringer, 1987;Smith and Pierce, 1987) and in many other types of cells (e.g., Bear, 1990;Thornhill and Laris, 1984, and references therein). It was therefore of interest to examine the effects of osmotic stress on the release of "Rb (generally accepted as a marker for K+) from promastigotes.…”

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confidence: 99%

Effect of osmolality on ⁸⁶Rb⁺ uptake and release by Leishmania donovani

Blum

1992

Journal Cellular Physiology

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Promastigotes from late-log phase cultures of Leishmania donovani were washed and resuspended in Hanks' Balanced Salt Solution without glucose or phenyl red but with 20 mM (N-[2-hydroxyethyl] piperazine-N'-[2-ethanesulfonic acid]) (HEPES) (HBSS-, 305 mOsm/kg). They were then added to a solution containing 86Rb such that the final osmolality and ionic composition was as desired. Samples were taken at known times and the amount of intracellular 86Rb was measured. Similarly, experiments were performed in which 86Rb was added to the cultures about 18 hr before collection, and the amount of 86Rb released from the washed cells was measured. Under iso-osmotic conditions only about 1.3% of the intracellular 86Rb was released in 900 sec. This increased about 4-fold if the osmolality was reduced from 305-153 mOsm/kg. This is much slower than the very rapid release of alanine in response to hypo-osmotic stress, indicating that alanine release is not via a non-specific pore. Reducing the temperature from 26 degrees C to 3-4 degrees C completely inhibits 86Rb release under iso-osmotic conditions and largely inhibits it under hypo-osmotic conditions. The rate of 86Rb release was not sensitive to K+ concentration and was not altered if chloride was replaced by sulfamate. Ouabain had no effect on either 86Rb uptake or release, but carbonylcyanide P-trifluoromethoxyphenylhydrazone (FCCP) reduced the rate of 86Rb release and, after about a 300 sec exposure, completely inhibited 86Rb uptake. Amiloride partially inhibited 86Rb release, but had no effect on uptake. A decrease in pH from 7.1-5.9 had little effect on 86Rb release under iso-osmotic conditions and slightly increased the rate of release under hypo-osmotic conditions, but it decreased the rate of uptake under both iso-osmotic and hypo-osmotic conditions. Cells taken from 3-day stationary phase cultures released 86Rb more slowly under iso-osmotic conditions than cells from late log phase cultures, but were more responsive to hypo-osmotic stress than were log phase cells. These data appear to rule out an [Na-K-Cl] transporter or a [K-Cl] cotransporter as the means of K+ release, but are consistent with the possibility that a K+/H+ exchanger is present. The possibility that other carrier systems may be present is also discussed.

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confidence: 99%

Effect of osmolality on ⁸⁶Rb⁺ uptake and release by Leishmania donovani

Blum

1992

Journal Cellular Physiology

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“…The phosphorylation of the 34-and 63-kDa proteins occurs with a slightly later time scale relative to the stress as compared to the Ca 2+ influx, requiring at least a few minutes to peak. Taurine efflux is evident by 10 rain and is complete within 1 hr (Amende & Pierce, 1980;Smith & Pierce, 1987). This time course suggests that the indicates medium without Ca 2+ plus 1 mM EGTA.…”

Section: Discussionmentioning

confidence: 79%

“…Second, phosphorylation of both ghost proteins after hypoosmotic exposure is reduced by Ca2+-free conditions. The same Ca 2+-free treatment also inhibits cell volume regulation in the Noetia blood cells by reducing taurine efflux, while leaving the KC1 efflux unaffected (Smith & Pierce, 1987). Although these data indicate that extracellular Ca 2+ is important for the osmotically induced phosphorylations and taurine efflux, results with the calmodulin antagonist provide evidence that the site of Ca 2 § action is an intracellular one.…”

Section: Discussionmentioning

confidence: 84%

“…In addition, external divalent cations, especially Ca 2+, play an important role in turning the osmolyte efflux on or off (Pierce & Politis, 1990). External concentrations of Ca z+ influence cell volume regulation and osmotically dependent free amino acid efflux in some systems, e.g., mussel (Modiolus) ventricle (Pierce & Greenberg, 1973); clam (Noetia) blood cells (Amende & Pierce, 1980;Smith & Pierce, 1987); and polychaete (Glycera) red coelomocytes (Costa & Pierce, 1983) and is required for organic osmolyte (sorbitol) efflux in rat kidney cells (Bevan, Theiss & Kinne, 1990). Hypoosmotically induced membrane permeability changes towards inorganic ion osmolytes also display a dependence upon Ca z+ in some cells: dog blood cells (Parker, 1983); human lymphocytes (Grinstein, Dupre & Rothstein, 1982); Ehrlich ascites cells (Hoffmann, Simonsen & Lambert, 1984); human red cells (Hoffman et al, 1980); Amphiuma red blood ceils (Cala, 1983); and toad bladder (Wong & Chase, 1986).…”

Section: Introductionmentioning

confidence: 99%

“…These cells volume regulate under hypoosmotic stress in a Ca 2+-and calmodulin-dependent manner (Smith & Pierce, 1987;Pierce et al, 1988, I989).…”

Section: Introductionmentioning

confidence: 99%

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Specific protein phosphorylation occurs in molluscan red blood cell ghosts in response to hypoosmotic stress

Politis

Pierce

1991

J. Membrain Biol.

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The regulation of cellular volume upon exposure to hypoosmotic stress is accomplished by specific plasma membrane permeability changes that allow the efflux of certain intracellular solutes (osmolytes). The mechanism of this membrane permeability regulation is not understood; however, previous data implicate Ca2+ as an important component in the response. The regulation of protein phosphorylation is a pervasive aspect of cellular physiology that is often Ca2+ dependent. Therefore, we tested for osmotically induced protein phosphorylation as a possible mechanism by which Ca2+ may mediate osmotically dependent osmolyte efflux. We have found a rapid increase in 32Pi incorporation into two proteins in clam blood cell ghosts after exposure of the intact cells to a hypoosmotic medium. The osmotic component of the stress, not the ionic dilution, was the stimulus for the phosphorylations. The osmotically induced phosphorylation of both proteins was significantly inhibited when Ca2+ was omitted from the medium, or by the calmodulin antagonist, chlorpromazine. These results correlate temporally with cell volume recovery and osmolyte (specifically free amino acid) efflux. The two proteins that become phosphorylated in response to hypoosmotic stress may be involved in the regulation of plasma membrane permeability to organic solutes, and thus, contribute to hypoosmotic cell volume regulation.

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Osmolyte permeability in molluscan red cells is regulated by Ca²⁺ and membrane protein phosphorylation: The present perspective

Pierce

1994

J. Exp. Zool.

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During the past several years, a number of studies on a variety of cell types have demonstrated the importance of Ca2+ in the control of the mechanism that produces cell volume recovery following a hypoosmotic stress. We have been studying the details of this control using the red blood cell from the bivalve mollusc, Noetia ponderosa, as a model. Volume recovery by these molluscan cells is a Ca2 + -sensitive process that involves initial Ca2+ entry, followed by phosphorylation of certain membrane-associated proteins and taurine efflux. This paper reviews the present state of those studies and presents a working hypothesis of the nature of the mechanism.

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CELL VOLUME REGULATION BY MOLLUSCAN ERYTHROCYTES DURING HYPOOSMOTIC STRESS: Ca²⁺EFFECTS ON IONIC AND ORGANIC OSMOLYTE EFFLUXES

Cited by 28 publications

References 24 publications

Effect of osmolality on ⁸⁶Rb⁺ uptake and release by Leishmania donovani

Effect of osmolality on ⁸⁶Rb⁺ uptake and release by Leishmania donovani

Specific protein phosphorylation occurs in molluscan red blood cell ghosts in response to hypoosmotic stress

Osmolyte permeability in molluscan red cells is regulated by Ca²⁺ and membrane protein phosphorylation: The present perspective

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CELL VOLUME REGULATION BY MOLLUSCAN ERYTHROCYTES DURING HYPOOSMOTIC STRESS: Ca2+EFFECTS ON IONIC AND ORGANIC OSMOLYTE EFFLUXES

Cited by 28 publications

References 24 publications

Effect of osmolality on 86Rb+ uptake and release by Leishmania donovani

Effect of osmolality on 86Rb+ uptake and release by Leishmania donovani

Specific protein phosphorylation occurs in molluscan red blood cell ghosts in response to hypoosmotic stress

Osmolyte permeability in molluscan red cells is regulated by Ca2+ and membrane protein phosphorylation: The present perspective

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CELL VOLUME REGULATION BY MOLLUSCAN ERYTHROCYTES DURING HYPOOSMOTIC STRESS: Ca²⁺EFFECTS ON IONIC AND ORGANIC OSMOLYTE EFFLUXES

Effect of osmolality on ⁸⁶Rb⁺ uptake and release by Leishmania donovani

Effect of osmolality on ⁸⁶Rb⁺ uptake and release by Leishmania donovani

Osmolyte permeability in molluscan red cells is regulated by Ca²⁺ and membrane protein phosphorylation: The present perspective