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Extracellular ATP activates receptor‐operated cation channels in mouse lacrimal acinar cells to promote calcium influx in the absence of phosphoinositide metabolism
Author(s) -
Sasaki T.,
Gallacher D.V.
Publication year - 1990
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1016/0014-5793(90)80782-e
Subject(s) - extracellular , chemistry , calcium , intracellular , microbiology and biotechnology , biophysics , acetylcholine , calcium in biology , biochemistry , endocrinology , biology , organic chemistry
In exocrine acinar cells a variety of neurotransmitters (e.g. acetylcholine) stimulate phosphatidylinositol 4,5‐bisphosphate hydrolysis elevating intracellular calcium to activate calcium‐dependent membrane currents (outward K + and inward Cl − ). This study shows that in lacrimal acinar cells extracellular application of ATP is also associated with outward and inward current responses; these, however, are not the result of phosphoinositide metabolism. ATP directly activates receptor‐operated cation channels which permit influx of Na + and Ca + (the inward current). The elevation in [Ca 2+ ], which results is sufficient to activate the outward K + current. ATP thus promotes Ca + influx in the absence of phosphoinositide metabolism.