Involvement of cytoskeletal integrity in the regulation of Cl and amylase secretion from rat parotid acinar cells

摘要

The cytoskeleton serves as a signal modulator for Ca2+ and cAMP-regulated cell functions including the secretion of ions and granule contents. The interaction between Ca2+ and cAMP signaling systems potentiates amylase secretion and suppresses CF secretion in the parotid glands. In this study, we investigated the role of the cytoskeleton in the modulation of Cl~ and amylase secretion from rat parotid acinar cells upon activation of each intracellular signaling system and their interaction. Cytochalasin D markedly inhibited the Ca2+-activated outwardly rectifying Cl~ current at positive membrane potentials and carbachol (CCh)-induced CF currents in the whole-cell configuration at -80 mV, whereas colchicine enhanced Cl~ currents Cytochalasin D, but not colchicine, markedly inhibited CCh-induced CF secretion Synergistic actions of CCh and forskolin on Cf and amylase secretion were observed even in the presence of cytochalasin D. These results suggest that the synergistic effects of Ca2+ and cAMP signaling systems on amylase and CF secretion do not require actin filament integrity but that secretion by the two signals themselves does require actin filament integrity.