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Exogenous ATP raises cytoplasmic free calcium in fura‐2 loaded piglet aortic endothelial cells
Author(s) -
Hallam Trevor J.,
Pearson Jeremy D.
Publication year - 1986
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(86)80019-9
Subject(s) - calcium , fura 2 , cytoplasm , chemistry , biophysics , microbiology and biotechnology , medicine , biochemistry , biology , cytosol , enzyme
Cultured piglet endothelial cells were grown to confluence on glass coverslips and loaded with the fluorescent Ca 2+ indicator, fura‐2. Using a dual‐wavelength excitation fluorescence spectrophotometer it was found that ATP caused a rapid transient elevation in [Ca 2+ ] i in the presence of extracellular calcium which decreased to a maintained elevated level. With no extracellular calcium ATP evoked a similar transient increase which returned to the basal level. Addition of 50 mM K + had no effect on [Ca 2+ ] i or on the effect of ATP on [Ca 2+ ] i in the presence of extracellular Ca 2+ . The data suggest that ATP causes both discharge of calcium from an intracellular pool and influx across the plasma membrane although this is unlikely to be via a voltage‐operated channel. ATP stimulated simultaneously the production of PGI 2 to a similar extent in the presence or absence of extracellular calcium. Elevated [Ca 2+ ] i may be an important activation pathway in the endothelial cell.