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Measurement of cytosolic free Ca 2+ in individual pancreatic acini
Author(s) -
Pralong William F.,
Wollheim Claes B.,
Bruzzone Roberto
Publication year - 1988
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(88)80989-x
Subject(s) - extracellular , bombesin , cytosol , chemistry , endocrinology , medicine , amylase , agonist , acinus , kinetics , biophysics , intracellular , enzyme , receptor , biochemistry , pancreas , biology , neuropeptide , physics , quantum mechanics
The kinetics of changes in cytosolic free Ca 2+ ([Ca 2+ ] i ) were determined in individual rat pancreatic acini by microfluorimetry. Three major findings are reported. First, at maximal stimulatory concentrations for amylase release, both caerulein and bombesin induced an initial rise in [Ca 2+ ] i followed by prolonged secondary oscillations of smaller amplitude. The latter effect was not observed with supramaximal doses of caerulein. Second, these cyclic changes were dependent, at least in part, on extracellular Ca 2+ . Finally, comparison of the threshold doses for [Ca 2+ ] i mobilization and enzyme discharge demonstrated that pathways independent of an elevation of [Ca 2+ ] i control the secretory activity of pancreatic acini at low, picomolar agonist concentrations.