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Regulation of cytosolic free Ca 2+ in cultured rat alveolar macrophages (NR8383)
Author(s) -
Zhang Guo H.,
Helmke Ronald J.,
Mörk AnnChristin,
Martinez J. Ricardo
Publication year - 1997
Publication title -
journal of leukocyte biology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.819
H-Index - 191
eISSN - 1938-3673
pISSN - 0741-5400
DOI - 10.1002/jlb.62.3.341
Subject(s) - biology , extracellular , inositol , zymosan , intracellular , receptor , purinergic receptor , cytosol , inositol trisphosphate , fura 2 , calcium , biophysics , endocrinology , microbiology and biotechnology , medicine , biochemistry , in vitro , enzyme
Ca 2+ mobilization in the rat alveolar macrophage cell line NR8383 was examined with the Ca 2+ ‐sensitive fluorescent probe Fura‐2. ATP and norepinephrine elicited a 108 and 46% increase, respectively, in cytosolic free Ca 2+ concentration ([Ca 2+ ] i ). Acetylcholine, nicotine, isoproterenol, substance P, and vasoactive intestinal polypeptide did not alter [Ca 2+ ] i . Inositol 1,4,5‐trisphosphate (IP 3 ) formation was also activated by ATP. The carbohydraterich cell wall preparation, zymosan, induced a gradual [Ca 2+ ] i increase only in the presence of external Ca 2+ , but did not activate IP 3 formation. This increase was abolished by laminarin and by removal of extracellular Ca 2+ , suggesting that the [Ca 2+ ] i increase was activated by β‐glucan receptors and mediated by Ca 2+ influx. This influx was significantly reduced by SKF96365, but not by nifedipine, ω‐conotoxin GVIA, ω‐agatoxin IVA, or flunarizine. These results suggest that release of intracellular Ca 2+ in NR8383 cells is regulated by P 2 ‐purinoceptors and that zymosan causes Ca 2+ influx via a receptor‐operated pathway. J. Leukoc. Biol. 62: 341–348; 1997.