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Forschungsdatenbank PMU-SQQUID

Cellular mechanisms of bradykinin-induced hyperpolarization in renal epitheloid MDCK-cells.
Lang, F; Paulmichl, M; Pfeilschifter, J; Friedrich, F; Wöll, E; Waldegger, S; Ritter, M; Tschernko, E;
Biochim Biophys Acta. 1991; 1073(3): 600-608.
Originalarbeiten (Zeitschrift)

PMU-Autor/inn/en

Paulmichl Markus
Ritter Markus

Abstract

Previous studies have demonstrated that bradykinin hyperpolarizes the cell membrane of subconfluent MDCK cells by increase of the potassium conductance. The present study has been performed to elucidate the intracellular mechanisms involved. To this end, the effects of bradykinin on the potential difference across the cell membrane (PD), on formation of inositol phosphates, and on intracellular calcium concentration (Cai) have been analyzed in cells without or with pretreatment with pertussis toxin or 12-O-tetradecanoylphorbol 13-acetate diester (TPA). In untreated cells, bradykinin leads to a transient increase of inositol 1,4,5-trisphosphate and inositol 1,3,4,5-tetrakisphosphate, increase of Cai, activation of potassium channels and hyperpolarization of the cell membrane. The effects of bradykinin on PD and Cai are still present in the absence of extracellular calcium. In cells pretreated with pertussis toxin the effect of bradykinin on inositol trisphosphate formation is almost abolished but bradykinin still leads to a transient increase of Cai and PD in the presence and absence of extracellular calcium. In cells pretreated with TPA the bradykinin-induced increase of inositol trisphosphate formation is blunted, the bradykinin-induced increase of Cai abolished, but the bradykinin-induced hyperpolarization still present. The observations indicate that bradykinin increases Cai in part by phorbol ester and pertussis toxin sensitive activation of phospholipase C. In addition, bradykinin is capable of enhancing Cai by utilizing pertussis toxin insensitive mechanisms. Furthermore, bradykinin is able to transiently enhance the potassium conductance without a general increase of intracellular calcium.


Useful keywords (using NLM MeSH Indexing)

Animals

Bradykinin/pharmacology*

Calcium/metabolism

Cell Line

Cell Membrane/drug effects

Dogs

Fluorescence

Hydrogen-Ion Concentration

Inositol Phosphates/biosynthesis

Ion Channels/drug effects

Kidney/drug effects*

Kidney/metabolism

Membrane Potentials/drug effects

Pertussis Toxin

Tetradecanoylphorbol Acetate/pharmacology

Virulence Factors, Bordetella/pharmacology


Find related publications in this database (Keywords)

CELL MEMBRANE POTENTIAL
POTASSIUM CHANNEL
CALCIUM, INTRACELLULAR
INOSITOL PHOSPHATE
PERTUSSIS TOXIN
PHORBOL ESTER