Involvement of cytoskeletal integrity in the regulation of Cl- and amylase secretion from rat parotid acinar cells.
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.
Kongo
Hiroyasu
H
Department of Oral Physiology, Graduate School of Biomedical Sciences, Hiroshima University, Hiroshima, Japan.
Hirono
Chikara
C
Sugita
Makoto
M
Iwasa
Yoshiko
Y
Shiba
Yoshiki
Y
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
D002712:Chlorides; D015638:Cytochalasin D; D002217:Carbachol; D000681:Amylases; D003078:Colchicine