Secretagogue induced calcium mobilization in single pancreatic acinar cells.

Microspectrofluorometry of fura-2 was utilized to monitor [Ca2+]i in single acinar cells stimulated with a cholinergic agonist and cholecystokinin. A similar amplitude of agonist induced Ca mobilization between single cell and populational approaches was observed. New findings in single cells not observable in populations of cells include: 1) the maintenance of a sustained elevation in [Ca2+]i above basal levels throughout agonist application, 2) the reloading of the agonist-sensitive Ca pool only following removal of the agonist and 3) the presence of oscillations of [Ca2+]i in response to agonist application which is enhanced at lower agonist concentrations.