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Forschungsdatenbank PMU-SQQUID

Effects of bradykinin on cell volume and intracellular pH in NIH 3T3 fibroblasts expressing the ras oncogene.
Ritter, M; Wöll, E; Häussinger, D; Lang, F;
FEBS Lett. 1992; 307(3): 36-70.
Originalarbeiten (Zeitschrift)

PMU-Autor/inn/en

Ritter Markus

Abstract

BCECF fluorescence has been applied to determine intracellular pH (pHi) in NIH 3T3 fibroblasts expressing the Ha-ras oncogene (+ras) and otherwise identical cells not expressing the oncogene (-ras). In +ras cells, pHi is significantly more alkaline (6.79 +/- 0.03 n = 12) than in -ras cells (6.64 +/- 0.02, n = 8). Bradykinin (100 nmol/l) leads to intracellular alkalinization in both +ras (to 6.96 +/- 0.04, n = 12) and -ras cells (to 6.85 +/- 0.02, n = 8). The effect of bradykinin is completely abolished in the presence of dimethylamiloride (100 mumol/l), which does not modify pHi in the absence of bradykinin. Similar to bradykinin, cell shrinkage by addition of 15 mmol/l NaCl to the extracellular fluid leads to intracellular alkalinization (by 0.08 +/- 0.01, n = 15). Cell volume is significantly greater in +ras cells (2.7 +/- 0.4 pl, n = 15) than in -ras cells (2.2 +/- 0.4 pl, n = 15). Bradykinin leads to cell shrinkage in both +ras cells (by 7 +/- 1%, n = 17) and -ras cells (by 5 +/- 1%, n = 15). The effect of bradykinin on cell volume can be reversed by the reduction of extracellular NaCl concentration by 15 mmol/l NaCl in +ras cells and by 7 mmol/l NaCl in -ras cells. This maneuver completely abolishes (in -ras cells) or blunts (in +ras cells) the alkalinizing effect of bradykinin. In conclusion, +ras cells are more alkaline than -ras cells. Bradykinin leads to further intracellular alkalinization by activation of the Na+/H(+)-exchanger, at least in part secondary to hormone-induced cell shrinkage.


Useful keywords (using NLM MeSH Indexing)

3T3 Cells

Amiloride/analogs*

derivatives

Amiloride/pharmacology

Animals

Bradykinin/antagonists*

inhibitors

Bradykinin/pharmacology*

Carrier Proteins/metabolism

Fluoresceins

Gene Expression

Genes, ras*/physiology

Hydrogen-Ion Concentration

Ion Channel Gating

Mice

Potassium Channels/physiology

Sodium-Hydrogen Antiporter

Transfection


Find related publications in this database (Keywords)

INTRACELLULAR PH
NA+/H+-EXCHANGER
CELL VOLUME
RAS ONCOGENE
BRADYKININ