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Manipulation of Intracellular Calcium in NCB‐20 Cells
Author(s) -
Garritsen Anja,
Cooper Dermot M. F.
Publication year - 1992
Publication title -
journal of neurochemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.75
H-Index - 229
eISSN - 1471-4159
pISSN - 0022-3042
DOI - 10.1111/j.1471-4159.1992.tb08890.x
Subject(s) - ionomycin , thapsigargin , phospholipase c , pertussis toxin , chemistry , intracellular , protein kinase c , microbiology and biotechnology , calcium , bk channel , biophysics , transient receptor potential channel , signal transduction , g protein , receptor , biology , biochemistry , organic chemistry
Abstract A number of lines of evidence indicate that the Ca 2+ and cyclic AMP signalling systems interact in NCB‐20 cells. However, to date, the regulation of [Ca 2+ ] i homeosta‐sis has not been studied in this cell line. The present study aimed to clarify our understanding of [Ca 2+ ] i homeostasis in these cells and to evaluate tools that manipulate [Ca 2+ ] i , independently of protein kinase C effects. Bradykinin, by a B 2 ‐receptor, elevated [Ca 2+ ] i by a pertussis‐toxin‐insensitive mechanism. The BK‐stimulated [Ca 2+ ] i rise originated from intracellular sources, without a contribution from Ca 2+ entry mechanisms. The effect of BK was precluded by pre‐treatment with thapsigargin and ionomycin—compounds that elevated [Ca 2+ ] i independent of phospholipase C activation. Both compounds, however, exerted effects in addition to stimulating release of Ca 2+ from BK‐sensitive stores; the BK‐sensitive Ca 2+ pool was a subset of the thapsigargin‐sensitive pool; ionomycin strongly stimulates Ca 2+ entry. Activation of protein kinases A and C attenuated the duration of the BK‐induced rise in [Ca 2+ ] i, without affecting the peak [Ca 2+ ] i , suggesting interference with the BK response at a step downstream of the activation of phospholipase C. Application of these approaches should enhance the delineation of the consequences of Ca 2+ mobilization on cyclic AMP accumulation.