ANALYSIS OF SPATIAL AND TEMPORAL CHARACTERISTICS OF CA2+ RELEASE IN PERMEABILIZED PAROTID CELLS

Ca2+ waves and oscillations have been observed during stimuli that gen erate inositol 1,4,5-trisphosphate (IP3) in several exocrine cells, in cluding rat parotid acinar cells. Although a model has been proposed t o explain the mechanism of the Ca2+ wave, there exists no direct evide nce to prove the model's validity. Analysis with a permeabilized cell system provides direct information about the properties of Ca2+ stores and Ca2+ release channels. We summarize here the experimental techniq ues that may be used to elucidate the spatial and temporal regulation of Ca2+ in a single permeabilized cell. The future applications of the se methods and the possible mechanisms of the Ca2+ wave are also discu ssed.