title: Involvement of cytoskeletal integrity in the regulation of Cl- and amylase secretion from rat parotid acinar cells.
abstract: 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 Cl- 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 Cl- currents in the whole-cell configuration at -80 mV, whereas colchicine enhanced Cl- currents. Cytochalasin D, but not colchicine, markedly inhibited CCh-induced Cl- secretion. Synergistic actions of CCh and forskolin on Cl- 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 Cl- secretion do not require actin filament integrity but that secretion by the two signals themselves does require actin filament integrity.
authors.affiliation: Department of Oral Physiology, Graduate School of Biomedical Sciences, Hiroshima University, Hiroshima, Japan.
authors.forename: Hiroyasu
authors.initials: H
authors.lastname: Kongo
authors.forename: Chikara
authors.initials: C
authors.lastname: Hirono
authors.forename: Makoto
authors.initials: M
authors.lastname: Sugita
authors.forename: Yoshiko
authors.initials: Y
authors.lastname: Iwasa
authors.forename: Yoshiki
authors.initials: Y
authors.lastname: Shiba
mesh_terms: D000681:Amylases / Q000378:metabolism*; D000818:Animals; D002217:Carbachol / Q000494:pharmacology; D002712:Chlorides / Q000378:metabolism*; D003078:Colchicine / Q000494:pharmacology; D015638:Cytochalasin D / Q000494:pharmacology; D003599:Cytoskeleton / Q000378:metabolism*; D008297:Male; D010306:Parotid Gland / Q000166:cytology / Q000201:enzymology / Q000378:metabolism*; D051381:Rats; D017208:Rats, Wistar
chemical_list: D002712:Chlorides; D015638:Cytochalasin D; D002217:Carbachol; D000681:Amylases; D003078:Colchicine