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Effect of SERCA Pump Inhibitors on Chemoresponses in Paramecium
Author(s) -
WASSENBERG JAMES J.,
CLARK KEVIN D.,
NELSON DAVID L.
Publication year - 1997
Publication title -
journal of eukaryotic microbiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.067
H-Index - 77
eISSN - 1550-7408
pISSN - 1066-5234
DOI - 10.1111/j.1550-7408.1997.tb05962.x
Subject(s) - paramecium , serca , electrophysiology , biology , extracellular , gtp' , depolarization , endoplasmic reticulum , calcium , microbiology and biotechnology , biophysics , atpase , neuroscience , medicine , biochemistry , enzyme
. Inhibitors of SERCA (sarcoplasmic/endoplasmic reticulum Ca 2+ ‐dependent ATPase) calcium pumps were used to investigate the involvement of internal Ca 2+ stores in the GTP response in Paramecium . External application of these inhibitors was found to dramatically alter the typical behavioral and electrophysiological responses of Paramecium to extracellular chemical stimulation. In particular, 2.5‐di‐tert‐butylhydroquinone (BHQ) strongly inhibited the backward swimming response of paramecia to externally applied GTP, though it did not inhibit the associated whirling response. BHQ also prolonged the normally brief electrophysiological response of these cells to GTP. BHQ completely blocked the behavioral and electrophysiological responses of Paramecium to extracellular Ba 2+ , but had no measurable effect on the behavioral or electrophysiological responses of these cells to another depolarizing stimulus, elevated external K + concentration. These results suggest the involvement of nonciliary Ca 2+ ions in the GTP and Ba 2+ responses.