scholarly journals Simultaneous changes of cell volume and cytosolic calcium concentration in macula densa cells caused by alterations of luminal NaCl concentration

2005 ◽  
Vol 563 (3) ◽  
pp. 895-901 ◽  
Author(s):  
Ruisheng Liu ◽  
A. Erik G. Persson
Keyword(s):  
Cell Volume ◽  
Calcium Concentration ◽  
Cytosolic Calcium ◽  
Macula Densa ◽  
Cytosolic Calcium Concentration ◽  
Nacl Concentration

Osmolality-induced changes in aldosterone secretion involve a chloride-dependent process

1995 ◽  
Vol 268 (1) ◽  
pp. R8-R13
Author(s):  
N. Hayama ◽  
W. Wang ◽  
E. G. Schneider
Keyword(s):  
Angiotensin Ii ◽  
Cell Volume ◽  
Calcium Concentration ◽  
Cytosolic Calcium ◽  
Chloride Ions ◽  
Methyl Sulfate ◽  
Sulfate Ion ◽  
Aldosterone Secretion ◽  
Cytosolic Calcium Concentration ◽  
Membrane Stretch

Alterations in extracellular osmolality have a powerful inverse effect on aldosterone secretion that is associated with sustained changes in cell volume. With dispersed bovine glomerulosa cells grown in primary culture, the effects of alterations in osmolality on cell volume measured by the distribution of [14C]urea and [3H]mannitol were determined in the presence and absence of chloride. In the presence of chloride, decreases in osmolality increased cell volume, whereas angiotensin II (< 4 x 10(-9) M) did not affect cell volume. When chloride was removed from the medium (replacing chloride with the impermeant methyl sulfate ion), cell volume decreased significantly, but basal aldosterone secretion was not altered. In the absence of chloride, the increases in cell volume, cytosolic calcium concentration, and aldosterone secretion induced by decreases in osmolality were significantly suppressed. The replacement of chloride with the methyl sulfate ion suppressed the increases in both cytosolic calcium concentration and aldosterone secretion induced by low (< 4 x 10(-9) M) but not high (4 x 10(-8) M) concentrations of angiotensin II. The results suggest that reductions in osmolality increase cell volume, partly by inducing an influx of chloride ions that contributes to the total net influx of water. Reductions in cell volume caused by an increase in osmolality or by replacing the chloride ion with the impermeant methyl sulfate ion may induce alterations in membrane stretch that may decrease the angiotensin II-induced increase in cytosolic calcium concentrations, which in turn suppresses aldosterone secretion.

scholarly journals Orientia tsutsugamushi Inhibits Apoptosis of Macrophages by Retarding Intracellular Calcium Release

2002 ◽  
Vol 70 (8) ◽  
pp. 4692-4696 ◽  
Author(s):  
Mee-Kyung Kim ◽  
Seung-Yong Seong ◽  
Ju-Young Seoh ◽  
Tae-Hee Han ◽  
Hyeon-Je Song ◽  
...  
Keyword(s):  
Intracellular Calcium ◽  
Calcium Concentration ◽  
Calcium Release ◽  
Cytosolic Calcium ◽  
Orientia Tsutsugamushi ◽  
Cytosolic Calcium Concentration ◽  
Infected Cells ◽  
Intracellular Calcium Release ◽  
Calcium Redistribution ◽  
In Cells

ABSTRACT Orientia tsutsugamushi shows both pro- and antiapoptotic activities in infected vertebrate cells. Apoptosis of THP-1 cells induced by beauvericin was inhibited by O. tsutsugamushi infection. Beauvericin-induced calcium redistribution was significantly reduced and retarded in cells infected with O. tsutsugamushi. Antiapoptotic activities of O. tsutsugamushi in infected cells are most probably due to inhibition of the increase in the cytosolic calcium concentration.

scholarly journals Protection against hydrogen peroxide cytotoxicity in Rat-1 fibroblasts provided by the oncoprotein Bcl-2: maintenance of calcium homoeostasis is secondary to the effect of Bcl-2 on cellular glutathione

1999 ◽  
Vol 340 (1) ◽  
pp. 291-297 ◽  
Author(s):  
Matthäus M. RIMPLER ◽  
Ursula RAUEN ◽  
Thorsten SCHMIDT ◽  
Tarik MÖRÖY ◽  
Herbert DE GROOT
Keyword(s):  
Cell Death ◽  
Calcium Concentration ◽  
Cell Injury ◽  
Cytosolic Calcium ◽  
Glutathione Metabolism ◽  
Transfected Cells ◽  
Cytosolic Calcium Concentration ◽  
Glutathione Status ◽  
Calcium Elevation ◽  
Reduced State

The oncoprotein Bcl-2 protects cells against apoptosis, but the exact molecular mechanism that underlies this function has not yet been identified. Studying H2O2-induced cell injury in Rat-1 fibroblast cells, we observed that Bcl-2 had a protective effect against the increase in cytosolic calcium concentration and subsequent cell death. Furthermore, overexpression of Bcl-2 resulted in an alteration of cellular glutathione status: the total amount of cellular glutathione was increased by about 60% and the redox potential of the cellular glutathione pool was maintained in a more reduced state during H2O2 exposure compared with non-Bcl-2-expressing controls. In our cytotoxicity model, disruption of cellular glutathione homoeostasis closely correlated with the pathological elevation of cytosolic calcium concentration. Stabilization of the glutathione pool by Bcl-2, N-acetylcysteine or glucose delayed the cytosolic calcium increase and subsequent cell death, whereas depletion of glutathione by DL-buthionine-(S,R)-sulphoximine, sensitized Bcl-2-transfected cells towards cytosolic calcium increase and cell death. We therefore suggest that the protection exerted by Bcl-2 against H2O2-induced cytosolic calcium elevation and subsequent cell death is secondary to its effect on the cellular glutathione metabolism.

TRAVELLING CALCIUM WAVES IN SYSTEMS WITH NON-DIFFUSING BUFFERS

2008 ◽  
Vol 18 (06) ◽  
pp. 883-912 ◽  
Author(s):  
BOGDAN KAZMIERCZAK ◽  
VITALY VOLPERT
Keyword(s):  
Structural Stability ◽  
Diffusion Coefficients ◽  
Calcium Concentration ◽  
Travelling Waves ◽  
Cytosolic Calcium ◽  
Calcium Waves ◽  
Cytosolic Calcium Concentration

The existence and structural stability of travelling waves of systems of the free cytosolic calcium concentration in the presence of immobile buffers are studied. The proof is carried out by passing to zero with the diffusion coefficients of buffers. Thus, its method is different from Ref. 13 where the existence is proved straightforwardly.

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